This is the 17756th most frequent Russian word.
укрепляли
"Strengthened" or "reinforced."
The verb 'укрепляли' here describes the action of strengthening or fortifying a physical structure by a group over a past period of time.
Они укрепляли стены замка, готовясь к обороне.
They reinforced the castle walls in preparation for defense.
In this example, 'укрепляли' is used metaphorically to describe the enhancement or deepening of a personal relationship.
Мы укрепляли свою дружбу через совместные путешествия.
We strengthened our friendship through shared trips.
Here, 'укрепляли' refers to supporting or reinforcing an abstract concept, such as conclusions, to make them more robust or credible.