The MS shows us a “lateen” better known as “lateener”. It is the general term applied to a vessel whose primary sail is a lateen; a triangle sail hung essentially fore-and-aft, with the luff lashed to a long yard. Sail topped over the stubby mast in going about.
Uganda 1998 3000s sgMS 1973, scott 1560.
Source: From Aak to Zumbra a Dictionary of World’s Watercraft.