The Collaborative International Dictionary of English v.0.48:
floatplane \floatplane\ n. a plane equipped with pontoons for landing or taking off from water. Syn: pontoon plane, seaplane. [WordNet 1.5]WordNet (r) 3.0 (2006):
floatplane n 1: a seaplane equipped with pontoons for landing or taking off from water [syn: floatplane, pontoon plane]