Definition of frass in English:

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Pronunciation: /fras/


1Fine powdery refuse or fragile perforated wood produced by the activity of boring insects.
Example sentences
  • We felt the fine, sharply scented frass of a carpenter ant colony with our fingertips.
  • By the end of the experiment, an average of 25% of the cotyledon of Q. alba acorns had been reduced to frass, while there was no apparent damage in any of the final sample of RO acorns.
1.1The excrement of insect larvae.
Example sentences
  • One downside of group dining is that chemical signals from the larvae and their frass can attract parasitoids.
  • As a bit of frass starts to emerge from the caterpillar, it pushes a hinged plate against a ring of blood vessels surrounding the anus.
  • The chemical analyses of the body and frass of Blepharida flavocostata revealed almost no match to the constituents found in B. biflora.


Mid 19th century: from German Frass, from fressen 'devour'.

For editors and proofreaders

Syllabification: frass

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