self-checkout; automated checkout
Refers to a checkout system where customers scan and pay for items themselves, common in supermarkets and convenience stores.
wasei-eigo (Japanese-coined English), from self regi(ster)
Self-checkout machines are increasing in supermarkets these days.
I paid at the self-checkout.
Wasei-eigo from English 'self' and 'register', shortened to セルフレジ.