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.
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.