What is the meaning of -ena?

feminine singular of -è

feminine singular of -é

forms feminine nouns from adjectives

-ene

1. an unsaturated hydrocarbon having at least one double bond; an alkene
2. an aromatic hydrocarbon based on benzene
3. a polymer derived from an alkene

an unsaturated hydrocarbon having at least one double bond; an alkene

an aromatic hydrocarbon based on benzene

a polymer derived from an alkene

a single-atom thick two-dimensional layer of atoms

definite plural form of -en

Forms the genitive plural of n-stem masculine, n-stem feminine, and some ō-stem feminine nouns

Forms the weak genitive plural of adjectives

feminine singular of -eno

feminine of -eno

Source: wiktionary.org