From Longman Dictionary of Contemporary Englishfloor-lengthˈfloor-length adjective [only before noun] DCCLONGlong enough to reach the floor floor-length curtains a floor-length skirt
Examples from the Corpus
floor-length• Give yourself plenty of room, particularly when dealing with floor-length curtains.• a floor-length evening gown• Her floor-length ice-blue satin dress was sleeveless and had a drop waist.• She caught the effect in the floor-length mirror and smiled.• She wore a floor-length pine green skirt with a matching jacket.• Between two floor-length windows that opened on to the street was a piano covered with a sheet. 