Sorry, Kanae. We all totally forgot about how much effort you put into it.
I almost forgot Koichi's face.
Forget about it. It’s water under the bridge.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means forget so the verb vocab version is to forget.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: Wait, what was (わす) the reading? I forget... What was it?