| Subject | English | Japanese |
| gen. | n efficient cause | 作用因 |
| gen. | n efficient cause | 動力因 |
| comp., MS | Efficient File Storage | 効率的なファイル保存 (A storage method in which a file is split into pieces that are stored and updated separately, and streamed together when a user requests the file) |
| comp., MS | Efficient File Transfer | 効率的なファイル転送 (A feature that breaks a file up into granular chunks so that during re-open and re-save scenarios only the differences between client and server are sent over the network) |
| tech. | efficient of fire pump | ポンプの性能 (ポンプのせいのう) |
| gen. | highly efficient | 効率の高い (adj) |
| gen. | n Japanese subsidy plan allowing refundable points when purchasing energy-efficient electronical appliances, etc. | エコ・ポイント |
| gen. | n Japanese subsidy plan allowing refundable points when purchasing energy-efficient electronical appliances, etc. | エコポイント (eko-pointo) |
| gen. | n vs making efficient | 効率化 (こうりつか) |
| gen. | most efficient section | 最有利断面 |
| construct. | water-efficient flushing | 節水型洗浄 (せっすい・がた・せんじょう) |