ALLITERATION - Alliteration is the repetition of the initial sounds of words (thus it is sometimes called 'head rhyme' or 'initial rhyme'), serving not only to link verses, but also to emphasise important words within the verse.

ANACRUSIS (also German: Auftakt) - '(Greek "the striking up of a tune") one of more initial syllables which are not part of a regular metrical scheme...' [PEPP 33]

CLITIC - A clitic is a morpheme that has syntactic characteristics of a word, but shows evidence of being phonologically bound to another word. [SIL]

(In English, the contraction spelled n't, as in don't, is a clitic)

DIPHTHONG - 'A union of two vowels pronounced in one syllable; the combination of a sonantal with a consonantal vowel' [OED] (the vowel sounds in the modern English words boy, lie, out are all diphthongs)

EXTRAMETRICALITY - property of not being counted by the metre. Confined in OE to certain words occurring at beginning of a line (beginning of the on-verse)

FOOT - A particular grouping of syllables. 'A measurable, patterned unit of poetic rhythm...a measure of rhythm consisting of 1 accented (stressed, "long") syllable (or 2, as in the spondee) and 1 or more unaccented (unstressed, "short", "slack") syllables' [PEPP 285]

Traditional English accentual or accentual-syllabic verse feet include: IAMB (iambus, iambic): x / (as in destroy); ANAPEST (anapaest, anapestic): x x / (as in intervene); TROCHEE (trochaic): / x (as in slowly); DACTYL (dactylic): / x x (as in merrily ); SPONDEE (spondaic): / / (as in amen); PYRRHIC: x x (as in to the). Iambic and anapestic feet are called ascending or rising feet; trochaic and dactylic, descending or falling.

'The foot bears a close resemblance to the musical bar: both are arbitrary and abstract units of measure which do not necessarily coincide with the phrasal units which they underlie' [PEPP 285]

ICTUS (Latin "beat") - 'Stress on a particular syllable of a foot or verse; rhythmical or metrical stress.' [OED]

Often synonymous with stress .

INFLEXION - 'The modification of the form of a word to express the different grammatical relations into which it may enter; including the declension of substantives, adjectives and pronouns, the conjugation of verbs, the comparison of adjectives and adverbs (but some treat the last under derivation or word-formation)' [OED]

(in modern English, the -s of cats is a nominal plural inflexion; the -ed of walked is a verbal past-tense inflexion)

METRE (also meter) - 'More or less regular poetic rhythm; the measurable rhythmical patterns manifested in verse; or the "ideal" patterns which poetic rhythms approximate. If "metre" is regarded as the ideal rhythmical pattern, then "rhythm" becomes "metre" the closer it approaches regularity and predictability. The impulse toward metrical organization seems to be a part of the larger human impulses toward order: metre is what results when the rhythmical movements of colloquial speech are heightened, organized and regulated so that pattern emerges from the relative phonetic haphazard or ordinary utterance. Metre is thus one of the fundamental and most subtle techniques of order available to the poet, like rhyme, line division, stanza form, and over-all structure...' [PEPP 496-7]

'"Metre" derives from the Greek term for "measure", and one way to investigate various meters or metrical systems is to examine what is being measured in each. On this basis, four metrical systems are generally--if not quite adequately--discriminated: the syllabic, the accentual, the accentual-syllabic, and the quantitative...Most Germanic poetries, including Old English, are based on accentual meter, as are most [modern] English poems in which the number of syllables varies (through trisyllabic substitution, for example) from line to line...[i]n accentual metre...only the accents are measured; syllables may vary in number, it being assumed that 3 or 4 syllables can be uttered in the same time as 1 or 2....In poetry, which is the most organic and "total" mode of verbal expression, metre (like the other formal elements) serves as one of the primary correlatives of meaning: since metre is an indispensable contributor to meaning, it follows that the metre of a poem, in and by itself, means something, and even that the metre maintains a portion, at least, of its meaning whether symbolic sounds are attached to it or not...In addition to serving as a major technique for the reinforcement of meaning, metre performs more general functions in a poem. It often establishes a sort of "distance" between both poet and subject and reader and subject by interposing a film of unaccustomed rhythmical ritual between observer and experience. It can thus help to control emotion and inhibit cliché responses in both poet and reader. This ritual "frame" in which metre encloses what is often perfectly everyday experience resembles the frame or artificial border of a painting....Metre, as a device of artificiality and unnaturalness, is thus a primary technique of artifice in poetry, just as similar conventions (the palpably artificial stone flesh of statues, for example) are primary techniques of artifice in the other arts. Metre also tends to suggest (since ordinary people don't speak in meter) the vatic role of the poet, just as it tends to invest with a mysterious air of permanence and authority the words which are cut to its pattern. The strange power of metre to burnish the commonplace has even tempted some thinkers to regard metrical patterns as Platonic forms, themselves inherently and permanently beautiful, which the poet perceives unconsciously and towards which he constantly impels his own utterance...' [PEPP 497-9]

MORPHOLOGY - the internal structure of words; see also morpheme
 MORPHEME - the smallest unit of meaning, which cannot be analysed into smaller forms; morphemes are meaningful units which may be smaller than words, e.g. in the word cats, there are two morphemes: cat and -s [the plural morpheme]

PHONOLOGY - the properties of the sounds of a language (often in opposition to morphology and syntax )

RESOLUTION (also German: Auflösung) - Metrical treatment of two syllables as one; various restrictions apply to resolution, including that the first syllable must be syllable

STRESS - 'The vocal emphasis received by a syllable as part of a metrical pattern. Stress is held by some linguists and prosodists to be equal to accent; it is held by others to be one of the constituents of accent; the terms is used by still others to mean metrical accent as distinguished from rhetorical accent' [PEPP 811]

Stressed syllables are those which are most prominent (often louder and longer than unstressed syllables). (in the word about, the first syllable is unstressed, the second stressed)

In this discussion, stressed syllables are symbolised by / (for primary, "louder" stress) and \ (for secondary, "weaker" stress) and x is used for unstressed syllables.

SYLLABLE - A syllable is always built upon a single vowel (which may be diphthongal in nature), which forms its core; it may also include an onset [consonants preceding the vowel] and/or a coda [consonants following the vowel], but need not (the words a, to, am, bat, train, blast are all monosyllables, i.e. one-syllable words)

 'A vocal sound or set of sounds uttered with a single effort of articulation and forming a word or an element of a word; each of the elements of spoken language comprising a sound of greater sonority (vowel or vowel-equivalent) with or without one or more sounds of less sonority (consonants or consonant-equivalents)' [OED]

'Linguistically, the domain of any degree of accent in spoken utterance. The syllable is the smallest measurable unit of poetic sound, the fundamental building-block of metrical structure' [PEPP 832]

heavy syllable is a syllable with a long vowel (or diphthong) and/or a coda (consonant following the vowel);a light syllable is a syllable with a short vowel (or diphthong) and no coda

SYNTAX -  'The arrangement of words (in their appropriate forms) by which their connexion and relation in a sentence are shown; the department of grammar which deals with the established usages of grammatical construction and the rules deduced therefrom: distinguished from accidence, which deals with the inflexional forms of words as such' [OED]

VERSE - A verse is the basic unit of Old English poetry. The 'ideal' verse in Old English has four syllables and two stresses , but many verses deviate in constrained ways from this pattern, so that it is more correct to say that a normal verse has four positions. Positions may be identical to syllables, but need not be - for example a consecutive series of unstressed syllables is generally counted as a single position. Verses are 'strung together' or linked by alliteration.

An on-verse is the first verse of a line (also called an a-verse); an off-verse is the second verse of a line (also called a b-verse): in Beowulf l.3 : (hú ðá æþelingas      ellen fremedon) - hú ðá æþelingas is the on-verse and ellen fremedon is the off-verse

[OED] = Oxford English Dictionary (Murray, James et al. (eds.). Oxford English Dictionary on CD-ROM. Oxford: Oxford Uni. Press, 1999 [2nd. ed.])
[PEPP] = Princeton Encyclopedia of Poetry & Poetics (Alex Preminger, ed. with Frank J. Warnke & O.B. Hardison, Jr., eds. Princeton (New Jersey): Princeton Uni. Press, 1965; enlarged edition, 1974)
[SIL] = Summer Institute of Linguistics' Glossary of Linguistic Terms [online] (Eugene E. Loos, ed. with Susan Anderson, Dwight H. Day, Jr., Paul C. Jordan, J. Douglas Wingate, eds.)