lock-up

The compound "lock-up" is a transparent phrasal verb turned noun, built from two robust Old English elements. The core, "lock," originates from the Proto-Germanic lukan, related to the physical act of fastening a door or enclosure. The particle "up," from Proto-Germanic upp, originally indicated direction but evolved to convey a sense of completion or finality when combined with verbs. The literal logic of "fastening completely" naturally extended to the figurative sense of confinement, first applied to securing a building for the night and later specializing to mean imprisonment. This semantic journey from a simple physical action to an abstract state of enforced confinement illustrates how Germanic compounds create nuanced meanings through the combination of concrete roots.

Structure: lock (verb) + up (particle) - lock: From Old English loc, meaning "a fastening, enclosure." It functions as the core verb, denoting the action of securing with a fastening. - up: From Old English up, upp, meaning "upward, to a higher position." It functions as an adverbial particle that intensifies or completes the verb, suggesting thoroughness, finality, or completeness.