paca \pa"ca\ (Pg. p[aum]"k[.a]; E. p[=a]"k[.a]), n. [Pg., from the native name.] 1. (Zool.) A large burrowing South American rodent ({Agouti paca} syn. {Cuniculus paca}, formerly {C[oe]logenys 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]