Dummy
来自Big Physics
late 16th century: from dumb + -y1. The original sense was ‘a person who cannot speak’, then ‘an imaginary fourth player in whist’ (mid 18th century), whence ‘a substitute for the real thing’ and ‘a model of a human being’ (mid 19th century).
wiktionary
From dumb + -y.
etymonline
dummy (n.)
1590s, "mute person," from dumb (adj.) + -y (3). Extended by 1845 to "figure representing a person," hence "counterfeit object, something that imitates a reality for mechanical purposes." In card games (originally whist, later bridge) "exposed hand of cards placed face-up," by 1736. Meaning "dolt, blockhead" is from 1796.
