The term "more tumaceous" refers to something that is softer, spongier or more swollen than usual. Its antonyms would be words that describe something that is harder, firmer or less swollen. Some antonyms for the term "more tumaceous" include compact, thin, rigid, taut, tight, skinny, slim, lean and muscular. These words describe things that are less plump or less soft, having less cushion or less flexibility. Conversely, "more tumaceous" can also imply excessive growth or expansion, and antonyms in this case would include words like restrained, restrained, limited or modest.