Latin, from combining form of Ancient Greek στέαρ (stear, “fat, tallow, suet”) + πυγή (pugē, “rump”).
1871 - The Descent of Man and Selection in Relation to Sex, Charles Darwin;
see Example below
From: The Descent of Man, and Selection in Relation to Sex
By Charles Darwin
New Edition, 1876
Part III. Sexual Reflection in Relation to Man, and Conclusion
Chapter XIX. Secondary Sexual Characters of Man