This is the 115th most frequent Portuguese word.
nova
"Nova" means "new" (feminine) in English.
In this case, 'nova' is used to describe the noun 'idea', suggesting that the idea might not appear to be recent or original.
Essa ideia não parece tão nova.
This idea doesn't seem so new.
Here, 'nova' describes the attribute 'new' of the noun 'bag'.
Comprei uma bolsa nova.
I bought a new bag.
The word 'nova' is used as an adjective describing the noun 'student', indicating she is new.