customer

1. (obsolete) A habitual patron, regular purchaser, returning client; a person or company who has a custom of buying from a particular business.obsolete

2. (informal) A person, especially one engaging in some sort of interaction with others.Examples: "a cool customer, a tough customer, an ugly customer"; "Pug could just see Slote's pale face under his fur hat. "I don't agree with you on that. He's a pretty tough customer, Hopkins.""; "This switch led to Philip Hammond becoming the Transport Secretary and he quickly proved to be a tricky customer, asking questions about rail spending and reining it back whenever possible."informal

3. (India, historical) A native official who exacted customs duties.Examples: "His houses […] are seized on by the Customer."; "The Customer should come and visit them."; "The several affronts, insolences, and abuses dayly put upon us by Boolchund, our chief Customer"Indiahistorical