noun
customers; clients
Refers to customers or clients, often in a business context. The word is somewhat formal and not extremely common in everyday conversation.
この店は来客筋が広い。
This shop has a wide range of customers.
来客筋に失礼のないように気をつけてください。
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.
Compound of 来客 (visitor, customer) and 筋 (line, source, connection). The exact historical derivation is uncertain, but the word likely emerged in commercial contexts to refer to the stream or type of customers.