weyk-
“to bend, to wind”bend, turn, wind
Root for bending/winding, yielding Latin vincire (to bind), English weak, wicker, wick.
Discussion
The PIE root *weyk- (to bend, to wind, to turn, to change) produced vocabulary spanning physical curvature and moral deviation — the concept that what is bent is also what has gone wrong.
Latin vīcis (a turn, a change, alternation — genitive form used as a noun) gave English: vicissitude (a turning of fortune, a change of circumstance), vicar (vicārius, one who serves "in the turn/place" of another — a substitute), vice (in the sense of "in place of" — vice-president), and the prefix vice- in all institutional substitution terms. The connection between turning and substitution is logical: the vicar turns into the place of the absent principal.
The word weak (OE wāc, from PGmc *waikwaz, from *weyk-) shows the moral extension: what is bent is structurally compromised, hence weak. German weich (soft, yielding) preserves the same development. The word wicker (woven flexible branches) preserves the physical bending sense: wicker is made by bending and winding pliable rods.
Old English wīcan (to yield, to give way) continues the verbal root — to yield is to bend before pressure.
The word witch (OE wicca/wicce) is sometimes connected to this root through the concept of bending or turning reality — though this etymology is disputed and some scholars derive it from *wik- (to be alive/animate) instead.
The root's conceptual arc — bending → yielding → weakening → substituting — shows how a physical image of curvature generated both structural vocabulary (wicker, weak) and institutional vocabulary (vicar, vice-president).
Notes
Pokorny 1130-1131. English wicker, weak, witch from Germanic.