noun
card security code; CVC; CVV
Refers to the 3- or 4-digit verification number on credit/debit cards, used for online transactions. A direct loanword from English.
from English security code
オンラインで買い物をするときは、カードのセキュリティーコードを入力してください。
When shopping online, please enter your card's security code.
Borrowed from English 'security code', referring to the card verification value (CVV/CVC) used in payment processing.