1. Of, relating to, or in the region of the uterus: the uterine canal; uterine contractions.
2. Having the same mother but different fathers.
3. Being enclosed and dark; womblike.

[Middle English, from Late Latin uterīnus, from Latin uterus, uterus.]

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.