This is the 577th most frequent Croatian word.
znak
"Znak" means "sign" in English.
The word 'znak' here refers to a 'sign', an observable indication or signal.
To je znak da trebamo krenuti.
That is a sign that we need to start.
In this sentence, 'znak' means a 'sign', specifically a road sign.
Cestovni znak pokazuje smjer prema gradu.
The road sign shows the direction towards the city.
Here, 'znak' is used to mean 'gesture', a visible action to demonstrate meaning.