This is the 634th most frequent Russian word.
знака
"Знака" is the genitive singular or nominative/accusative plural form of "знак," meaning "sign" or "symbol" in English.
The word 'знак' refers to a traffic sign in this context.
На обочине дороги я заметил старый дорожный знак.
On the side of the road, I noticed an old traffic sign.
The word 'знак' here refers to a gesture or indication made to communicate.
Он подал мне знак рукой, чтобы я подошёл.
He gave me a sign with his hand to come closer.
The word 'знак' in this sentence represents a symbolic representation or gesture, signifying respect.