| Subject | English | Japanese |
| gen. | n a paddy moist all year due to improper irrigation | 湿田 |
| law | n Act for Identification, etc. by Mobile Voice Communications Carriers of Their Subscribers, etc. and for Prevention of Improper Use of Mobile Voice Communications Services | 携帯電話不正利用防止法 |
| gen. | n improper billing | 不正請求 (ふせいせいきゆう) |
| gen. | n improper bookkeeping | 不正会計処理 |
| gen. | improper conduct | 間違え (e.g. between man and woman) |
| gen. | improper conduct | 間違い ichi1 news1 nf07 (e.g. between man and woman, まちがい) |
| gen. | n improper fraction | 仮分数 (kabunsū) |
| phys. | improper integral | 異常積分 (いじょう・せきぶん) |
| gen. | improper integral | 特異積分 (tokui-sekibun) |
| phys. | improper orthogonal matrix | 変格直交行列 (へんかく・ちょっこう・ぎょうれつ) |
| gen. | improper resolution | 不当決議 |
| gen. | n vs improper use | 誤使用 |
| law | n improper use of a privilege | 権利乱用 |
| law | n improper use of a privilege | 権利濫用 (けんりらんよう) |
| law | n Mobile Phone Improper Use Prevention Act | 携帯電話不正利用防止法 |
| gen. | n trying to correct an unborn child's improper position so that the head comes out first | 逆子体操 |
| gen. | n vs using improper words | 失言 news2 nf29 |