- The fourth letter of the Greek alphabet. See Table at alphabet. (noun)
- An object shaped like a triangle. (noun)
- A usually triangular alluvial deposit at the mouth of a river. (noun)
- A similar deposit at the mouth of a tidal inlet, caused by tidal currents. (noun)
- Mathematics A finite increment in a variable. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.