Simple Definition of barnacle

from our Learner's Dictionary

barnacle

noun

ˈbɑɚnɪkəl

plural barnacles

: a kind of small shellfish that attaches itself to rocks and the bottoms of boats underwater

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“Barnacle.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/barnacle. Accessed 21 Jun. 2026.

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