| insuffizient | insufficient |
| Insuffizienz | insufficiency |
| suffizient | sufficient |
| ineffizient | inefficient |
| Suffizienz | sufficiency |
| Ineffizienz | inefficiency |
| inoffiziell | informal |
| Koeffizient | coefficient |
| effizient | efficient |
| infiziert | infected |
| Herzinsuffizienz | cardiac insufficiency |
| Insurgent | insurgent |
| insistent | insistent |
| süffisant | smug |
| Effizienz | efficiency |
| defizient | deficient |
| Suizident | suicide |
| indifferent | indifferent apathetic |
| Insignien | regalia |
| Instabilität | instability |