Meaning

noun spots before the eyes caused by opaque cell fragments in the vitreous humor and lens

noun a debt instrument with a variable interest rate tied to some other interest rate (e.g. the rate paid by T-bills)

noun a wanderer who has no established residence or visible means of support

originFrom float + -er (suffix forming agent nouns). Compare Old English flota (“boat, ship", also "sailor, pirate”, literally “floater”), whence Middle English flote (“a fleet of ships", also, "a float, flotation device”).

Etymology from Wiktionary, CC BY-SA 3.0