all-out

The compound adjective 'all-out' is a relatively modern formation, emerging in the late 19th to early 20th century. It originates from the phrasal verb 'to go all out,' meaning to exert oneself to the utmost limit. The morpheme 'all,' with its Proto-Germanic roots signifying completeness, combines with 'out,' an Old English adverb of direction and extent. This combination creates a powerful figurative sense of holding nothing back, of extending one's effort entirely outward and exhaustively. The term's logic vividly captures the concept of total, unreserved commitment, moving from a literal spatial description to an abstract intensifier of effort and scope.

Structure: all (entire) + out (to the fullest extent) - all: From Old English eall, meaning "entire, whole, every." It functions as an intensifier indicating totality. - out: From Old English ūt, meaning "outward, away, to the fullest extent." It functions as an adverb modifying 'all' to emphasize completeness.