yóu
cause
Original meaning:
helmet
Depicts a kind of helmet worn by warriors. Based on the original meaning "helmet", now written as 胄. The current meaning is a phonetic loan.
Evolution

Oracle script
(~1250-1000 BC)
Bronze script
Early Western Zhou (~1000 BC)
Seal script
Chu (Warring States: 475-221 BC)
Clerical script
Eastern Han dynasty (25-220 AD)Regular script
ModernDefinitions
yóu
cause, reason; from; to follow; it is for...to; reason; cause; because of; due to; to; to leave it (to sb); by (introduces passive verb)
Component uses
Iconic component in 1 character (1 verified)
Simplified component in 1 character (1 verified)
Unknown component in 1 character (1 verified)
Sources
黃德寬《古文字譜系疏證》p.587