noun
big spender; whale
Nightlife industry slang for a customer who spends a lot of money, especially in host/hostess clubs, bars, or similar establishments. Derived from 太っ腹な客 (generous customer).
あの店は太客が多くて、いつも賑わっている。
That place has a lot of big spenders and is always lively.
彼はクラブで太客として知られている。
He is known as a whale at the club.