i-adjective
naive; unsophisticated; innocent
Negative form of すれる (to become worldly-wise or jaded), describing someone who is still innocent, unworldly, or not street-smart. Often used in casual speech.
彼はまだすれてなくて、純粋なところがいい。
He's still naive, and I like that pure side of him.
都会に出てきたばかりで、すれてない感じがする。
Having just come to the city, she seems unsophisticated.