adjective: Having well-shaped buttocks
pronounced as: (kal-uh-PIJ-ee-uhn)
from the Greek calli- (beautiful) + pyge (buttocks).
"And it hasn't been lost on modern film directors that a nice set of tights can showcase the callipygian assets of a well-formed leading man."
Heroes in Hosiery; South China Morning Post (Hong Kong); Jul 20, 2006.
Thank you Anu Garg at A.Word.A.Day!
I think I will have the opportunity to use this word. . . .