prothonotary warbler

noun
  1. a wood warbler, Protonotaria citrea, of the eastern U.S., having an orange-yellow head and underparts, and bluish-gray wings and tail.

Origin of prothonotary warbler

An Americanism dating back to 1780–90; so called because its coloration resembles the robes traditionally worn by prothonotaries
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018