- Acting, moving, or capable of acting or moving quickly; swift. (adjective)
- Accomplished in relatively little time: a fast visit. (adjective)
- Acquired quickly with little effort and sometimes unscrupulously: made a fast buck scalping tickets. (adjective)
- Quick to understand or learn; mentally agile: a class for the faster students. (adjective)
- Indicating a time somewhat ahead of the actual time: The clock is fast. (adjective)
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.