interjection
Colloquial interjection used to strongly affirm or agree with what was just said, similar to 'you bet' or 'absolutely'.
「手伝ってくれる?」「おうとも!」
"Can you help me?" "Of course!"
「明日の試合、勝てる?」「おうとも、任せとけ!」
"Can we win tomorrow's game?" "Absolutely, leave it to me!"