有 効(ゆうこう)

ゆうこう

な-adjective

valid, effective

See also: 友好(ゆうこう) (friendship, amity)

1. valid, in effect

Legally or officially acceptable and usable.

This ticket is still valid.

This coupon is valid until next month.

Please check the expiration date of your passport.

有効期限 = expiration date (literally: validity period)

The contract is valid until next March, so it needs to be renewed by then.

This discount card is valid for one year from issue, and becomes invalid automatically when it expires.

無効 = invalid (opposite of 有効)

2. effective, useful

Producing the intended or desired result.

To think of an effective method.

Let's use our time effectively.

有効に使う = to use effectively

I think this method is effective.

Exercise is one of the effective means of maintaining health.

有効な手段 = effective means

It is said that recycling is important in order to make effective use of limited resources.

有効活用 = effective utilization

USAGE: 有効(ゆうこう) is used for both (1) validity of documents, tickets, etc., and (2) effectiveness of methods, measures, etc.

COMMON PATTERNS:

CONTRAST:

NOTE: Do not confuse with 友好(ゆうこう) (friendship), which has the same reading.

Related Words

core

Added 2026.1.13 1:03 · Revised 2026.5.27 5:08

03500/03645_yuukou