Dull; slow; not sharp mentally or physically. (Often appears in speech as 鈍い.)
そのナイフは鈍くて肉がうまく切れない。
That knife is dull and doesn't cut meat well.
彼は時々判断が鈍いことがある。
He is sometimes slow in his judgment.
朝の眠気で反応が鈍かった。
My reactions were sluggish because of morning drowsiness.