The rhythmically significant stress in the articulation of words, giving some syllables more relative prominence than others. In words of two or more syllables, one syllable is almost invariably stressed more strongly than the other syllables. In words of one syllable, the degree of stress normally depends on their grammatical function; nouns, verbs, and adjectives are usually given more stress than articles or prepositions. The words in a line of poetry are usually arranged so the accents occur at regular intervals, with the meter defined by the placement of the accents within the foot. Accent should not be construed as emphasis.
Sidelight: Two degrees of accent are natural to many multi-syllabic English words, designated as primary and secondary.
Sidelight: When a syllable is accented, it tends to be raised in pitch and lengthened. Any or a combination of stress/pitch/length can be a metrical accent.
Sidelight: A semantic shift in accent can alter meaning. In the statement, "give me the book," for example, the meaning can be altered depending on whether the word "me" or the word "book," receives the more prominent stress. In metrical verse, the meter might help determine the poet's intent, but not always.
Sidelight: In English, when the full accent falls on a vowel, as in PO-tion, that vowel is called a long vowel; when it falls on an articulation or consonant, as in POR-tion, the preceding vowel is a short vowel. In the classical Greek and Latin quantitive verse, however, long and short vowels referred to duration, i.e., how long they were held in utterance.
(See also Cadence, Ictus, Modulation, Rhythm, Sprung Rhythm, Wrenched Accent)
(Compare Caesura, Slack)

This definition is in context to Poetry. See more contextual defintions for Accent.