water pill wa·ter·pill uncommon noun 1. any substance that tends to increase the flow of urine Synonymsdiuretic drugdiureticwater pill Related words Broader terms drug Narrower terms chlorthalidoneethacrynic acidfurosemideindapamidemannitolthiazide WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
