1. A proposition that is maintained by argument.
2. A dissertation advancing an original point of view as a result of research, especially as a requirement for an academic degree.
3. A hypothetical proposition, especially one put forth without proof.
4. The first stage of the Hegelian dialectic process.
5. 1. The long or accented part of a metrical foot, especially in quantitative verse.
   2. The unaccented or short part of a metrical foot, especially in accentual verse.
6. Music. The accented section of a measure.

[Latin, from Greek, from tithenai, to put. Senses 5 and 6, Middle English, from Late Latin, lowering of the voice, from Greek, downbeat, from tithenai.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.