Definition of field mark in English:
A visible mark or characteristic that can be used in identifying a bird or other animal in the field.
- The wing bars, eye-rings, tail spots, and rump patches of a bird are the field marks that distinguish it from every other bird.
- The next step in identifying the critter is what you thought you should be concentrating on all the while - its field marks.
Definition of field mark in:
- British & World English dictionary