1.
unnecessary; useless; needless
Not needed or serving no purpose; in set phrases, there is no need for something.
2.
not allowed; to be avoided (on notices and in set phrases)
Used in fixed phrases and on notices to mean that something must not be done.
Common expressions
- 心配無用: no need to worry
- 遠慮は無用だ: there's no need to hold back
- 無用の長物: a useless thing that only takes up space, a white elephant
- 問答無用: no arguing; without discussion
Watch out
天地無用 on a parcel means 'do not turn upside down' (literally 'top and bottom: reversing not allowed'), not 'either way up is fine'. Many Japanese speakers misread it too.