early 14c., "small pool of dirty water," frequentative or diminutive of Old English pudd "ditch," related to German pudeln "to splash in water" (compare poodle). Originally used of pools and ponds as well. Puddle-duck for the common domestic duck is by 1846.
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.