This is the 12282nd most frequent Russian word.
испытаний
"Испытаний" means "tests" or "trials" in English.
The word 'испытаний' is used to refer to 'trials' in the sense of challenges or tests in life.
Он много пережил в жизни, полную испытаний.
He went through a lot in life, full of trials.
Here 'испытаний' refers to 'tests,' specifically scientific or technical trials to evaluate something.
Для проведения испытаний нового оборудования требуются специальные условия.
Special conditions are required to conduct tests of the new equipment.
In this context, 'испытаний' involves 'tests' examining material properties, such as strength or durability.