This is the 140th most frequent Estonian word.
kuhu
"Where to."
This use of 'kuhu' introduces a subordinate clause describing uncertainty about direction or destination.
Ma ei tea, kuhu minna.
I don't know where to go.
In this sentence, 'kuhu' asks for the location where an action should be performed, specifically placing an item.
Kuhu ma panen selle raamatu?
Where should I put this book?
Here, 'kuhu' is used as an interrogative word to ask about a destination.