Customer /ˈkʌstəmə/ (n.) The buy side. The “client”. The one for whom we do all of what we do. the one that is not the dealer. Perhaps an end user; more likely a rent-extracting intermediary between the financial word of extractorship and the ultimate client, a kindly old granddad who cares only for feeding the ducks with his granddaughter and would be horrified at the things perpetrated in his name and with his money.