This is the 5770th most frequent Russian word.
просеять
"Просеять" means "to sift" or "to sieve."
The word 'просеять' means to sift in this context, which involves passing flour through a sieve to remove clumps.
Мы решили просеять муку перед выпечкой.
We decided to sift the flour before baking.
Here, 'просеять' means to sift in a metaphorical sense, as separating relevant information from non-relevant.
Учитель помог нам просеять важные факты из текста.
The teacher helped us sift out the important facts from the text.
In this sentence, 'просеять' metaphorically means to carefully examine or filter something in order to find key elements.