The Collaborative International Dictionary of English v.0.48:
Loculus \Loc"u*lus\, n.; pl. Loculi. [L., little place, a compartment.] 1. (Zool.) One of the spaces between the septa in the Anthozoa. [1913 Webster] 2. (Bot.) One of the compartments of a several-celled ovary; loculament. [1913 Webster]