1.
standard, staple, classic, go-to
Something widely recognized as a reliable, popular, or time-tested choice. Originally a retail term for items kept permanently in stock, now used broadly for anything considered a classic or safe bet.
Usage
Originally a retail and fashion industry term referring to items that remain in stock across seasons (定番商品). Now widely used in everyday conversation for anything considered a tried-and-true favorite or classic choice — foods, songs, tourist spots, gifts, and more.
Often modifies another noun directly: 定番メニュー (standard menu item), 定番ソング (classic song), 定番コーデ (go-to outfit).