Combination of two weapons (戈), based on the original meaning "kill", now written as 殘. The current meaning is a phonetic loan.

Evolution

Oracle script

(~1250-1000 BC)

Seal script

Chu (Warring States: 475-221 BC)

Seal script

Shuowen (~100 AD)

Clerical script

Eastern Han dynasty (25-220 AD)

Regular script

Modern