pre-noun adjectival
practiced; skilled; experienced
Describes someone who is adept at something through practice or experience. Used attributively before nouns.
手慣れた手つきで包丁を扱う。
He handles the kitchen knife with practiced hands.
彼女は手慣れた様子で書類を整理した。
She organized the documents with an experienced air.
Compound of 手 (hand) and the past form of 慣れる (to get used to), literally 'hand-accustomed'. The exact historical derivation is uncertain, but the meaning is transparent from its components.