Stopgap rhymes with:
ascap, automap, backslap, belnap, bootstrap, burlap, catnap, corcap, dimetapp, flytrap, handicap, hubcap, kidnap, kneecap, lightcap, madcap, midcap, millsap, milsap, mishap, mousetrap, overlap, realcap, recap, roadcap, rocap, skycap, smallcap, westcap, wiretap, yonhap