This is the 6703rd most frequent Korean word.
유효
Valid; effective.
Here, '유효' (yuh-yo) is used in conjunction with '기간' (gi-gan), meaning 'validity period,' to indicate that the ID's validity is no longer active.
이 신분증은 유효기간이 지났습니다.
This ID card has expired.
The word '유효' (yuh-yo) here means 'valid' in terms of being active or usable, often applied to coupons, memberships, or documents.
이 쿠폰은 다음 주까지 유효합니다.
This coupon is valid until next week.
In this context, '유효' (yuh-yo) refers to something being 'valid' in a logical or justifiable manner.