This is the 970th most frequent Russian word.
удара
The Russian word "удара" means "of a strike" or "of a blow" (genitive singular form of "удар").
Here, 'удара' refers to a physical force or impact.
Её шаг был силой удара молота.
Her step was with the force of a hammer's blow.
In this sentence, 'удара' speaks of the movement caused by impacting waves.
От удара волн корабль качнулся.
From the strike of the waves, the ship rocked.
Here, 'удара' is used metaphorically to describe an unexpected unfortunate event.