paca (Pg. päk&adot_;; E. pāk&adot_;), n. [Pg., from the native name.] 1. (Zoöl.) A large burrowing South American rodent (Agouti paca syn. Cuniculus paca, formerly Cœlogenys paca), having blackish brown fur, with four parallel rows of white spots along its sides; the spotted cavy. It is closely allied to the agouti and the Guinea pig and is highly esteemed as food.[1913 Webster]