WordReference Random House Unabridged Dictionary of American English © 2026
der•trum
(dûr′trəm),USA pronunciation n., pl. -tra (-trə).USA pronunciation [Ornith.]
- Birdsthe extremity of the maxilla of a bird's bill, esp. when hooked or differentiated from the rest of the bill, as in pigeons and plovers.
- Greek dértron membrane, derivative of dérein to skin; compare dérma derma1
- Neo-Latin
- 1885–90