This is the 6670th most frequent Russian word.
narva
"Narva" is not a Russian word; it is likely a reference to Narva, a city in Estonia.
The word 'нарву' here is a verb form of 'нарвать', meaning to pick or gather, referring to the action of collecting something, in this case, flowers.
Я нарву свежих цветов для букета.
I will pick fresh flowers for the bouquet.
The word 'нарва' here refers to a fanciful or poetic name for a plant growing among stones, illustrating its usage as a noun.
На берегу реки растет нарва из камней.
On the riverbank grows a rosebay among the stones.
Here 'Нарва' is a proper noun, specifically the name of a city in Estonia, showing its usage as a singular noun.