| Subject | English | Estonian |
| sociol. | challenge of the era | ajastu väljakutse (helga.k) |
| med., health., anim.husb. | challenge virus | nakatamisviirus |
| sociol. | epochal challenge | ajastu väljakutse (helga.k) |
| comp., MS | HIP challenge | inimsuhtlust tõendav küsimus (A challenge meant to be easily solved by humans, while remaining too hard to be economically solved by computers) |
| health., anim.husb. | homologous challenge | nakatamine homoloogse tüvega |
| industr. | industrial challenge | tööstusalane küsimus |
| comp., MS | payment instrument challenge | maksevahendi kontrollimine (A fraud prevention mechanism that attempts to verify that an individual using a payment instrument is authorized to use or is the owner of that instrument) |