Definition of swimming crab
: any of numerous marine crabs especially of the family Portunidae that have some of the joints of one or more pairs of legs flattened and fringed so as to serve as fins
Join MWU now and get access to America’s largest dictionary, with:
- 300,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up swimming crab? Please tell us where you read or heard it (including the quote, if possible).