This is the 544th most frequent Afrikaans word.
sak
Bag.
Here, 'sak' refers to a physical container, like a bag or sack.
Ek sit my boek in my sak.
I put my book in my bag.
In this context, 'sak' is used as a verb meaning 'to go to bed' or 'to lay down'.
Sy sak elke aand vroeg in die bed.
She goes to bed early every evening.
Here, 'sak' is used as a part of the phrase 'in die sak gesak', describing an action where the ball ends its motion in the bag or pocket, as in billiards.