誰何 すいか
suika

Noun
Suru Verb

1. challenging (an unknown person); asking a person's identity

Transitive
いきなり本人 ほんにん誰何 すいかするのも無粋 ぶすい かんがえました。
ikinari honninni suika suru nomo busuito kangaemashita.
I thought it would be boorish to challenge his identity without warning.