The Collaborative International Dictionary of English v.0.48:
Sperm \Sperm\, n.[Contr. fr. spermaceti.] Spermaceti. [1913 Webster] Sperm oil, a fatty oil found as a liquid, with spermaceti, in the head cavities of the sperm whale. Sperm whale. (Zool.) See in the Vocabulary. [1913 Webster]WordNet (r) 3.0 (2006):
sperm oil n 1: an animal oil found in the blubber of the sperm whale