customers; clients
Refers to customers or clients, often in a business context. The word is somewhat formal and not extremely common in everyday conversation.
This shop has a wide range of customers.
Please be careful not to be rude to the clients.
顧客 is a standard business term for 'customer' or 'client', more frequently used than 来客筋.
Formed from 来客 “visitor, customer” and 筋, which here denotes a class, quarter, or source of customers.