clo·trim·a·zole (kl?-tr?m??-z?l?)n. A broad-spectrum antifungal drug, C22H17ClN2, used topically to treat a variety of superficial fungal infections, including candidiasis and ringworm.[c(h)lo(ro)- + tr(i)- (from its three phenyl groups) + im(id)azole.]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.