From Longman Dictionary of Contemporary Englishbe an old hand (at something)be an old hand (at something)EXPERIENCEDto have a lot of experience of something I’m an old hand at this game. → old
Examples from the Corpus
be an old hand (at something)• These were old hands, and Dawn Run was effectively still a novice.• Helms is an old hand at backroom politics.• Habitat is an old hand at changing habits of a lifetime.• Blue is an old hand at such compositions and has never had any trouble with them.• Pete Zimmerman is an old hand at water initiatives.• We are old hands in the public-school system. 