Wiktionary
n. (context idiomatic English) A person who is experienced at a certain activity.
WordNet
Usage examples of "old hand".
He looked at his dry old hand and it seemed to him that in this atmosphere, he had himself become more reptilian than human.
Being an old hand at seeking emergency shelter, he had not simply stuck his head in the cave and crawled forward.
Xar leaned forward, suddenly, laid his hand over Haplo's, laid his gnarled old hand over Haplo's heart.
And Superglue is quite an old hand at attaching fake fingernails -- a practice that has sometimes had grisly consequences when the tiny clear superglue bottle is mistaken for a bottle of eyedrops.
As for Good, he rose and wrung his hands over the brave man who had given his life to save him, and, though I am an old hand, I felt a lump grow in my throat.
Lawrence Pritchard Waterhouse, the old hand, went for a stroll along the Manila Bay seawall.