n.
A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.
acrosomal ac'ro·so'mal (-sō'məl) adj.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.