köken: Two derivations appear to have credence. * From noun 痴 (woko → oko, “foolishness, ridiculousness, outrageousness”). The sense development would have been laughable, funny, odd. * Similar to the formation of 床しい (yukashii, “elegant, refined, admirable; reminiscent, in accordance with”) from verb 行く (yuku, “to go”), from the sense of having a quality to make one want to go towards, from verb 招く…
köken: The word possibly originally meant "wasteful, diminishing, useless" (in which case, compare hupa for semantic shift), in which case it might be related to haaska and derived from haja-.
köken: Etymology tree Proto-Indo-European *h₂éd Proto-Italic *ad Proto-Italic *ad- Latin ad- Old French a- Old French muser Old French amuser Middle French amuser French amuserbor. Esperanto amuzi Esperanto -a Esperanto amuza From amuzi + -a.