noun
A type of barnacle that is commonly found on rocky shores and attaches itself to surfaces using a hard shell made of calcium carbonate.
-
The acorn barnacle is a type of marine crustacean that attaches itself to rocks along the shoreline.
-
I saw a bunch of those little acorn barnacles clinging to the dock at low tide.
-
Check out those tiny acorn barnacles stuck to the side of the boat!
-
Like an acorn barnacle, she was firmly attached to her beliefs and wouldn't budge.