Source : Webster's Revised Unabridged Dictionary (1913)

Vinegarroon \Vin`e*gar*roon"\, n. [Cf. Sp. vinagre vinegar.]
   A whip scorpion, esp. a large Mexican species ({Thelyphonus
   giganteus}) popularly supposed to be very venomous; -- from
   the odor that it emits when alarmed.

Source : WordNet®

vinegarroon
     n : large whip-scorpion of Mexico and southern United States
         that emits a vinegary odor when alarmed [syn: {Mastigoproctus
         giganteus}]