suru verb (special), intransitive verb
become dull; lose sharpness; become insensitive
Describes a decline in mental sharpness, sensitivity, or skill. Often used for senses, intuition, or ability becoming blunted over time.
年をとると感覚が鈍する。
As you get older, your senses become dull.
長い休みで腕が鈍した。
My skills got rusty over the long break.