Barnacle has 4 different meanings across 1 category:
Noun
marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces
European goose smaller than the brant; breeds in the far north
A marine crustacean of the subclass Cirripedia that attaches itself to submerged surfaces such as tidal rocks or the bottoms of ships.
To connect with or attach.