a difficult person to deal with
Teenage girls can be tough customers for their parents.
The new agent, however, is a tough customer, and in his quality of Clerk of Petty Sessions dabbles in legal lore.
A tough customer was tio Paella, and no one said a good word for him.
It soon became evident that she was not a man-of-war; but she might be a privateer, and if so, would prove a tough customer.
The newcomer was a tough customer, and should certainly have gone in first.
He had the impression that she was, in his own phraseology, “a tough customer.”
That ship out there is a big fellow, and will prove a tough customer.
It was surely a test, for the old bear had been a tough customer and his hide was half an inch thick and as hard as sole leather.
Hes a tough customer and Ive got a hunch we wont get any cooperation from him.
Well, all I got to say is, let him keep his hands off my boy Tobe, or he'll find out the kind of a tough customer I am.
Robert is the tough customer; Mark the highly civilized gentleman.