cte·​nid·​i·​um | \ -ēəm\
plural ctenidia\ -​ēə \

Definition of ctenidium

1 : the gill of a mollusk consisting typically of a respiratory structure that resembles a comb or feather, has a main stem with lateral lamellae, and is developed from the inner side of the mantle distinguished from ceras
2 : a structure consisting of a row of spines resembling the teeth of a comb on the head or thorax, or both, of certain fleas

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History and Etymology for ctenidium

New Latin, from cten- + -idium

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appealing forcibly to the mind or reason

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