The Collaborative International Dictionary
Balanoid
Balanoid \Bal"a*noid\, a. [Gr. ba`lanos acorn + -oid.] (Zo["o]l.) Resembling an acorn; -- applied to a group of barnacles having shells shaped like acorns. See Acornshell, and Barnacle.
Wiktionary
balanoid
a. (context zoology English) Resembling an acorn; applied to a group of barnacles with shells shaped like acorns.