What does nota augēns mean in Latin?

nota augēns, a noun, means “nota augens”.

What is the genitive of nota augēns?

The genitive singular is notae augentis. nota augēns is first declension.

nounfirst declension

nota augēns f (genitive notae augentis)

declension
form	singular	plural
nominative	nota augēns	notae augentēs
genitive	notae augentis	notārum augentium
dative	notae augentī	notīs augentibus
accusative	notam augentem	notās augentīs notās augentēs
ablative	notā augentī notā augente	notīs augentibus
vocative	nota augēns	notae augentēs

From nota (“mark, sign; critical mark or remark; note”) + augēns (“increasing, augmenting”).