Where does “one-armed bandit” come from?

one-armed bandit (English) comes from English one-armed, from English armed, from English Arm, from Middle English arm, from Old English earm, from Proto-West Germanic arm, from Proto-Germanic armaz, from Proto-Indo-European h₂ermos — to fit, to fix, to put together.

one-armed bandit (English): A gaming machine having a long arm-like handle at one side that a player pulls down to make reels spin; the player wins money or tokens when certain combinations of symbols line up on these reels

Definitions

  1. A gaming machine having a long arm-like handle at one side that a player pulls down to make reels spin; the player wins money or tokens when certain combinations of symbols line up on these reels

Ancestry of “one-armed bandit”, step by step

one-armed bandit traces back through two separate lines of ancestry.

via English one-armed

StepLanguageWordMeaning
1Englishone-armedHaving only one arm
2EnglisharmedEquipped, especially with a weapon; Prepared for...
3EnglishArmAbbreviation of Armenian
4Middle Englisharmarm; poor; miserable, wretched
5Old Englishearmarm; poor, miserable
6Proto-West Germanicarmarm; poor, miserable; pitiful, pitiable
7Proto-Germanicarmazarm; poor, miserable; pitiful, pitiable
8Proto-Indo-Europeanh₂ermos
9Proto-Indo-Europeanh₂er-to fit, to fix, to put together

via English bandit

StepLanguageWordMeaning
1EnglishbanditOne who robs others in a lawless area, especially...
2Italianbanditobandit, outlaw; past participle of bandire
3Italianbandireto announce; to ban; to banish
4LatinbannioI proclaim; I proscribe
5Frankishbannijan
6Proto-Germanicbannanąto proclaim, to order; to summon; to ban
7Proto-Indo-Europeanbʰeh₂-to shine, glow light; to speak, say
8Proto-Indo-Europeanbʰeh₂-s-ri-
Every word from Proto-Indo-European h₂er-