IPA: //ˈfloʊtˌpleɪn//
KK: /ˈfloʊtˌpleɪn/
A type of airplane that has floats instead of wheels, allowing it to land on and take off from water.
The floatplane landed smoothly on the lake, ready to pick up passengers.
Floatplane → It is formed from "float" (from Old English *flōtan*, meaning to float or to flow) and "plane" (from Latin *planus*, meaning flat or level). The word describes an aircraft designed to take off and land on water, hence it floats on the surface.
Think of an aircraft that 'floats' on water ('float') and is 'flat' ('plane') — that's how a floatplane operates.
No commonly confused words.