'zealot' originates from Greek, specifically the word 'ζηλωτής' (zēlōtēs), where 'ζηλόω' (zēloō) meant 'to be zealous or enthusiastic.'

'ζηλωτής' transformed into the Latin word 'zelotes,' and eventually became the modern English word 'zealot' through Old French 'zelote.'

Initially, it meant 'a member of a Jewish sect,' but over time it evolved into its current meaning of 'a fanatical person.'