This is the 2049th most frequent Polish word.
kątem
"At an angle" or "in the corner."
The phrase 'kątem oka' literally means 'with the corner of the eye' and is used idiomatically to describe peripheral vision.
Spojrzał kątem oka, aby upewnić się, że wszystko jest w porządku.
He glanced out of the corner of his eye to make sure everything was fine.
Here, 'kątem' refers to the 'corner' of a spatial location, indicating a physical angle in the room.
Ukryli bagaże w kątem pokoju, aby były mniej widoczne.
They hid the luggage in the corner of the room to make it less visible.
In this case, 'kątem' is used metaphorically to indicate a peripheral topic or aspect related to one's interests.