noun
old fox; cunning old person; schemer
Figurative expression for a shrewd, experienced person who is not easily fooled. Often carries a nuance of slyness or craftiness, like an old fox who knows all the tricks.
あの政治家は古狐だから、簡単には騙されない。
That politician is an old fox, so he won't be easily deceived.
彼は業界の古狐で、裏の事情にも詳しい。
He's an old-timer in the industry and knows all the inside details.
Compound of 古 (old) and 狐 (fox). The figurative meaning derives from the folkloric image of an old fox as a cunning, experienced creature.