- Any of various grasses of the genus Avena, especially A. sativa, widely cultivated for their edible grains. (noun)
- The grain of any of these plants, used as food and fodder. (noun)
- Archaic A musical pipe made of an oat straw. (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.