This is the 453rd most frequent Estonian word.
kestnud
The Estonian word "kestnud" means "lasted" or "endured" in English.
Here, "kestnud" is used as the past participle of "kestma" to describe an ongoing action duration.
Projekt on kestnud kolm kuud.
The project has lasted three months.
In this sentence, "kestnud" indicates the elapsed time of the action (lasting) in the past and is paired with a negation.
Tema haigus ei olnud kestnud kaua.
His illness had not lasted long.
This usage of "kestnud" forms a question, referring to the duration of an ongoing action.