Meaning

noun marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces

noun European goose smaller than the brant; breeds in the far north

originUncertain, with long-debated origin. From Middle English barnakille, from earlier bernake, bernekke, most likely from Old Northern French bernaque (“barnacle”) (compare French barnache), probably from Medieval Latin barneca (“limpet”), probably from Gaulish (compare Welsh brennig, Irish bairneach), from Proto-Celtic *barannīkos, from *barinā (“rock, rocky ground”) (compare Old Irish barenn…

Etymology from Wiktionary, CC BY-SA 3.0