- Being in physical motion: active fish in the aquarium. (adjective)
- Functioning or capable of functioning. (adjective)
- Marked by energetic activity; busy: active stock and bond markets; spent an active day sightseeing. (adjective)
- Involving or requiring physical exertion and energy: an active workout at the gym. (adjective)
- Being in a state of action; not quiescent: active hostilities along the border. (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.