Often taken to be a denominative verb 'to make bright, enlighten' to an adjective *argu- (“bright”), from Proto-Indo-European *h₂erǵ-u (“white”), amd thus cognate with Ancient Greek ἄργυρος (árguros) and Hittite [script needed] (ḫarki-, “bright, white”). If so, compare English declare (literally “to make clear”) for the sense development.
Duchesne-Guillemin, Laroche and Melchert deny the above etymology and instead compare arguo with the semantically better-fitting Hittite [script needed] (arkuwā(i)-, “state one's case, make a plea”).
- I show, prove, assert, declare, make clear.
- I reprove, accuse, charge with.
- I blame, censure.
- I denounce as false.