Where does “unanimosity” come from?

unanimosity (English) comes from English -ity, from Middle English -ite, from Old French -ité, from Latin -itās, from Proto-Indo-European -teh₂ts, from Proto-Indo-European -teh₂, from Proto-Indo-European -tós — Creates verbal adjectives from verb stems.

Ancestry of “unanimosity”, step by step

StepLanguageWordMeaning
1English-ityUsed to form a noun from an adjective;...
2Middle English-ite
3Old French-ité-ity
4Latin-itās
5Proto-Indo-European-teh₂tsUsed to form nouns representing state of being
6Proto-Indo-European-teh₂Used to form nouns representing state of being
7Proto-Indo-European-tósCreates verbal adjectives from verb stems
Every word from Proto-Indo-European -tósEvery word from English -ityEvery word from Latin -itās