1] a small vessel, a boat (see photo)
derivation: from a presumed derivative of (4143)
http://bible.crosswalk.com/Lexicons/Greek/grk.cgi?number=4142&version=kjv

(4143)
1] a ship
derivation: from (4126)
http://bible.crosswalk.com/Lexicons/Greek/grk.cgi?number=4143&version=kjv

(4126)
to sail, navigate, travel by ship
derivation: another form for pleuo {plyoo'-o}, which is used as an alternate in certain tenses, probably a form of (4150) (through the idea of plunging through the water)
http://bible.crosswalk.com/Lexicons/Greek/grk.cgi?number=4126&version=kjv

(4150)
1] to wash: with reference to clothing
derivation: a prolonged form of an obsolete pluo (to "flow")
http://bible.crosswalk.com/Lexicons/Greek/grk.cgi?number=4150&version=kjv