forthwith

The word "forthwith" is a compound formed from two Old English prepositions/adverbs, "forth" and "with." In its earliest Middle English usage, the phrase "forth with" carried a more literal spatial sense of "along with" or "forward together." Over time, the two words fused into a single adverb, and the meaning shifted from a sense of physical accompaniment to a purely temporal one, emphasizing immediate sequence. The logic of the evolution lies in the concept of one action proceeding forward in direct association with another, leading to the modern abstract meaning of "without any intervening time or delay."

Structure: forth + with forth (Old English): forward, onward; indicating movement or progression. with (Old English): against, opposite to, near; indicating association or accompaniment.