chinstrap

Noun

chinstrap (plural chinstraps)

1. A strip of leather or material used to fasten a hat or helmet under the chin.
   • A bridle, the chin-strap or chain.1777, John Richardson, A Dictionary, Persian, Arabic, and English, page 752
   • Such a deficit was not likely long to escape notice: the regiment was halted in the midst of a manœuvre, and, in the pause that ensued, Nosey demanded, in a grunt of thunder, how, without a chinstrap, I could expect my cap to stick upon my head.1842, “Waifs of the Waters”, in The Sporting Review
2. A form of beard that follows the jawline but does not cover the rest of the chin.

   Synonyms:

   chin strip

3. A band of colour below a bird's mouth, resembling the chinstrap of a helmet.
   • A miniature look-alike of the Canada Goose, with a partial white necklace instead of a white chinstrap.2003, Roger Tory Peterson, Peter Alden, Birds, page 10
   • The dark slate-grey plumage contrasting strongly with white 'chinstrap' is shared only by Blue Eared-pheasant, but their ranges do not overlap.2010, Phil McGowan, Steve Madge, Pheasants, Partridges & Grouse, page 313