This is the 5886th most frequent Russian word.
регистрировали
"Registered."
The word "регистрировали" is used in past tense to indicate who performed the action of registering.
Мы регистрировали участников конференции утром.
We registered the conference participants in the morning.
Here, "регистрировали" is used to describe a past action where registration was performed by the organizers.
Организаторы уже регистрировали всех прибывших.
The organizers have already registered all the arrivals.
In this sentence, "регистрировали" reflects past documentation activity conducted by authorities.