noun Ornithology.

the bone at the posterior end of the spinal column in birds, formed by the fusion of several caudal vertebrae.

Origin of pygostyle

1870–75; < Greek pȳgo- (combining form representing pȳgḗ rump) + stŷlos pillar
Related formspy·go·styled, adjectivepy·go·sty·lous, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for pygostyle

Historical Examples of pygostyle