Where does “одиноко” come from?

одиноко (Russian) comes from Russian одино́кий, from Russian оди́н, from Old East Slavic оди́нъ, from Proto-Slavic edìnъ, from Proto-Balto-Slavic edīˀnas, from Proto-Balto-Slavic aiˀnas, from Proto-Indo-European óynos — one; single.

одиноко (Russian): alone; in a lonely manner; short neuter singular...

Definitions

alone; in a lonely manner; short neuter singular...

Ancestry of “одиноко”, step by step

Step	Language	Word	Meaning
1	Russian	одино́кий	solitary, single, lone
2	Russian	оди́н	—
3	Old East Slavic	оди́нъ	—
4	Proto-Slavic	edìnъ	one
5	Proto-Balto-Slavic	edīˀnas	—
6	Proto-Balto-Slavic	aiˀnas	one
7	Proto-Indo-European	óynos	one; single

Every word from Proto-Indo-European óynos →Every word from Proto-Balto-Slavic aiˀnas →Every word from Proto-Balto-Slavic edīˀnas →