It is an adjective and it means "to smell". It has other interesting meanings and they are commonly used. The first meaning is "to be hammy" and it is used to describe a person or their acting that is unnatural and uses emotions too much. The second meaning is "to be fishy" and it is used to describe something that is suspicious.
Meg and Amy are talking about a movie.
- Meg : Have you ever seen "PS, I Love You"?
「PS, I Love You」、見たことある？ - Amy : Yes, I've watched it so many times that I memorized most of the lines.
うん、何度も見たから、ほとんどのセリフを覚えちゃった。 - Meg : I like Gerry Kennedy. He told his girlfriend "I know what I want, because I have it in my hands right now. You". He is so cute!
ゲリーケネディっていいよね。彼が彼女に、「僕が欲しいものは分かっているんだ。なぜなら、今こうして僕の腕の中にある。君だよ。」って言うの。格好良い！ - Amy : Really? That's so cheesy!
本気？くっさー(or臭い)！
Ken and Leo are talking at their office.
- Ken : Do you want me to help with you task?
作業、手伝おうか？ - Leo : No thank you. I can handle it myself.
いい、大丈夫。自分でやるよ。 - Ken : Can I get you a coffee?
コーヒー入れようか？ - Leo : What? You're a bit off today. You usually leave just after you finish your work.
何？何か臭いな。いつも自分の仕事が終わったら、すぐ帰るじゃん。 - Ken : Can you please lend me 100 dollars? I'll pay you back tomorrow.
100ドル貸してくれない？明日返すから。 - Leo : That explains it.
そういう事ね。