from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The short or unaccented part of a metrical foot, especially in quantitative verse.
- n. The accented or long part of a metrical foot, especially in accentual verse.
- n. Music The upbeat or unaccented part of a measure.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The stronger part of a musical measure or a metrical foot.
- n. The elevation of the hand, or that part of the bar at which it is raised, in beating time; the weak or unaccented part of the bar, opposed to the thesis.
from the GNU version of the Collaborative International Dictionary of English
- n. That part of a foot where the ictus is put, or which is distinguished from the rest (known as the thesis) of the foot by a greater stress of voice.
- n. That elevation of voice now called metrical accentuation, or the rhythmic accent.
- n. The elevation of the hand, or that part of the bar at which it is raised, in beating time; the weak or unaccented part of the bar; -- opposed to
from The Century Dictionary and Cyclopedia
- n. In prosody: Originally, the metrically unaccented part of a foot, as opposed to the thesis or part which receives the ictus or metrical stress.
- n. In prevalent modern usage, that part of a foot which bears the ictus or metrical accent, as opposed to the metrically unaccented part, called the thesis.
- n. In physiol. acoustics, a periodical increase in the intensity of a sound, producing a rhythmical effect.
Middle English, raising of the voice, from Late Latin, raising of the voice, accented part of a metrical foot, from Greek, raising of the foot (marking the upbeat), the unaccented part of a metrical foot, from aeirein, to lift; see wer-1 in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
Ancient Greek ἄρσις (ársis, "lifting"), from αἴρω (aírō, "I lift"). (Wiktionary)