Where does “kromnomo” come from?

kromnomo (Esperanto) comes from Esperanto nomo, from French nom, from Old French nom, from Latin nōmen, from Latin est, from Proto-Indo-European h₁ésti, from Proto-Indo-European h₁es- — to be.

kromnomo (Esperanto): byname; nickname; cognomen

Definitions

byname; nickname; cognomen

Ancestry of “kromnomo”, step by step

kromnomo traces back through two separate lines of ancestry.

via Esperanto nomo

Step	Language	Word	Meaning
1	Esperanto	nomo	name
2	French	nom	A name, "especially" a last name or family name;...
3	Old French	nom	name
4	Latin	nōmen	name
5	Latin	est	third-person singular present active indicative...
6	Proto-Indo-European	h₁ésti	to be
7	Proto-Indo-European	h₁es-	to be

via Esperanto krom

Step	Language	Word	Meaning
1	Esperanto	krom	except, save; besides
2	Russian	кро́ме	except, besides
3	Old East Slavic	кромѣ	outside, aside, away
4	Proto-Slavic	kroma	edge, boundary; slice

Every word from Proto-Indo-European h₁es- →Every word from Proto-Indo-European h₁ésti →Every word from Latin est →