weakness

Proto-Germanic waikwaz described something pliant, something that bends without breaking. The Old English adjective wāc, attested by the ninth century, applied to flexible wood, slack ropes, and limbs that gave way under pressure. The abstract noun wācnes arrived shortly after, built with the -nes suffix that turns qualities into conditions.

By the Middle English period, around 1300, the word had become wēknesse and begun its migration inward. Langland used it in Piers Plowman (c. 1370) to describe a failure of will as much as a failure of body. The pivot was slow: physical limpness and moral limpness shared the same word long before they were held apart as separate ideas.

The Germanic root waikwaz connects to Old Norse veikr and Dutch week, both meaning soft or pliant. The shared ancestor points to a time when yielding was not yet a character judgment but simply a physical description. German weich still means soft today, carrying none of the moral weight that English weak accumulated over centuries.

By the early seventeenth century, Shakespeare was consistently using weakness to cover appetite and temptation alongside bodily frailty. A character could be weak in constitution or weak in resolve, and the same word covered both conditions without distinction. The word completed its journey from bent wood to bent will: what had described pliant willow now described pliant character.