cas·trate (k?s?tr?t?)tr.v. cas·trat·ed, cas·trat·ing, cas·trates 1. To remove the testicles of (a male); geld or emasculate.2. To remove the ovaries of (a female); spay.3. To deprive of virility or spirit; emasculate.n. An individual who is incapable of reproduction as a result of removal, destruction, or inactivation of the gonads.[Latin castr?re, castr?t-; see kes- in Indo-European roots.]cas?trat·er, cas?tra·tor n.cas·tra?tion n.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.