Where does “infanterio” come from?

infanterio (Esperanto) comes from Spanish infantería, from Spanish Infante, from Old Spanish ifante, from Latin īnfāntem, from Latin īnfāns, from Latin īn-, from Latin în, from Latin en — in.

infanterio (Esperanto): infantry

Definitions

infantry

Ancestry of “infanterio”, step by step

Step	Language	Word	Meaning
1	Spanish	infantería	infantry
2	Spanish	Infante	infant
3	Old Spanish	ifante	—
4	Latin	īnfāntem	—
5	Latin	īnfāns	speechless, inarticulate
6	Latin	īn-	un-, non-, not
7	Latin	în	in, at, on, upon, from (space)
8	Latin	en	lookǃ beholdǃ; reallyǃ?; come onǃ
9	Proto-Italic	en	in
10	Proto-Indo-European	h₁én	in

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