n. pl. la·cu·nae (-nē) or la·cu·nas 1. An empty space or a missing part; a gap: "self-centered in opinion, with curious lacunae of astounding ignorance" (Frank Norris). 2. Anatomy A cavity, space, or depression, especially in a bone, containing cartilage or bone cells. [Latin lacūna; see LAGOON.] la·cunal adj. |
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