Where does “infinitif” come from?

infinitif (Middle French) comes from Late Latin infinitivus, from Latin īnfīnītus, from Latin īn-, from Latin în, from Latin en, from Proto-Italic en, from Proto-Indo-European h₁én — in.

Ancestry of “infinitif”, step by step

Step	Language	Word	Meaning
1	Late Latin	infinitivus	unlimited, indefinite; infinitive; the infinitive
2	Latin	īnfīnītus	boundless, unlimited, endless
3	Latin	īn-	un-, non-, not
4	Latin	în	in, at, on, upon, from (space)
5	Latin	en	lookǃ beholdǃ; reallyǃ?; come onǃ
6	Proto-Italic	en	in
7	Proto-Indo-European	h₁én	in

Words derived from “infinitif”

infinitive
infinitief
infinitif

Every word from Proto-Indo-European h₁én →Every word from Latin īn- →Every word from Proto-Italic en →