Sterculiaceous \Ster*cu`li*a"ceous\, a. [NL. Sterculia, the typical genus, fr. L. Sterculius the deity that presided over manuring, from stercus dung. So called because one of the original species is fetid.] (Bot.) Of or pertaining to a natural order ({Sterculiace[ae]}) of polypetalous exogenous plants, mostly tropical. The cacao ({Theobroma Cacao}) is the most useful plant of the order.