| Subject | English | Japanese |
| gen. | n complex compound number | 複素数 (a + bi, fukusosū) |
| comp., MS | complex number | 複素数 (A number in the form a + bi, where a and b are real numbers and i = sqrt(-1) , so that bi is imaginary unless b = 0, fukusosū) |
| phys. | complex number | 複素数 (fukusosū) |
| math. | n complex number | 虚数 (kyosū) |
| gen. | n complex imaginary number | 複素数 (fukusosū) |
| phys. | complex number field | 複素数体 (fukusosū-tai) |
| phys. | conjugate complex number | 共役複素数 (きょうやく・ふくそすう) |