flu·tic·a·sone propionate (flo?o-t?k??-s?n?, -z?n?)n. A synthetic corticosteroid, C25H31F3O5S, used as a topical anti-inflammatory and antipruritic, as a nasal spray in the treatment of rhinitis, and as an inhalant, in combination with salmeterol, in the treatment of asthma and chronic obstructive pulmonary disease.[flu(oro)- + tic- (probably shortening and rearrangement of carbothioate, one of its constituents) + (meth)asone (as in dexamethasone).]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.