onion fly
noun
Definition of onion fly
1 : a dipterous insect of the family Anthomyiidae whose larva feeds on onion bulbs; especially : an originally European insect (Hylemya antiqua) now widely distributed in America
2 : an insect (Tritoxa flexa) of the family Otitidae with habits like those of the onion fly —called also black onion fly
Explore M-W
There's more!
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 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 onion fly? Please tell us where you read or heard it (including the quote, if possible).
Writing? Check your grammar now!