The compound adjective "too-big" is formed by combining the intensifying adverb "too" with the adjective "big." The adverb "too" originates from Old English 'tō', which carried the sense of "in excess," a meaning that has persisted. "Big" entered Middle English, likely from Old Norse, to describe size or importance. The combination logically follows English syntactic patterns, where "too" modifies an adjective to indicate a degree beyond what is desirable or acceptable. Thus, "too-big" literally means "excessively large," a concept directly built from the transparent meanings of its two constituent parts.

Structure: too (excessively) + big (large) - too: From Old English 'tō', meaning "in addition, also, excessively." It functions as an adverb of degree. - big: From Middle English 'bigge', of uncertain origin, possibly from a Scandinavian source. It functions as an adjective meaning large in size.