1550s, "to dip a little and often," hence "to wet by splashing," probably a frequentative of dab. Figurative sense of "do superficially" attested by 1620s. Related: Dabbled; dabbling. An Ellen Dablewife is in the Lancashire Inquests from 1336.

"to splash, dabble in water," 1580s, from plash (n.) and also imitative (compare Dutch plassen, German platschen). An earlier form of splash. Related: Plashed; plashing.

mid-15c., "to dabble in water, poke in mud," from puddle (n.); the extended sense in iron manufacture is "turn and stir (molten iron) in a furnace (to expel oxygen and carbon)." Related: Puddled; puddling.

"to dabble, wade in water," 1520s, probably cognate with Low German paddeln "tramp about," frequentative of padjen "to tramp, to run in short steps," from the source of  pad (v.). Related: Paddled; paddling. Meaning "to move in water by means of paddles" is a different word (see paddle (v.3)).