- any of several paper wasps of the family Vespidae, having black and bright yellow bands.
- Slang. a yellow capsule of phenobarbital.
Origin of yellow jacket
An Americanism dating back to 1790–1800
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for yellow jacket
Thereafter I dived and hopped like a frog through the brush and water, until I came out beyond that yellow-jacket barrage.Everyday Adventures
A young half-breed with a complexion like a yellow-jacket asked me if I would have my boots blacked.Roughing It
Mark Twain (Samuel Clemens)
Now once in a while a babe is found hard to wean; the same may be said of a yellow-jacket.On a Donkey's Hurricane Deck
R. Pitcher Woodward
And there are still others, where Buddy collided with the yellow-jacket, that I find I cannot read at all.Tenting To-night
Mary Roberts Rinehart
The Professor was powerless, but lay in Tim's arms biting, kicking, and curled up like a yellow-jacket interested with an enemy.
- US and Canadian any of several social wasps of the genus Vespa, having yellow markings on the body