Hello It comes from the word 귀엽다 which means cute 귀염둥이 is more of a slang and it means something like cutie Hope this helps ^^

귀염둥이 is consist of 귀염+둥이. 1. 귀염 is noun from 귀엽다 which is verb. ※ 귀엽다(verb) → 귀여운(adjective) → 귀염(noun) 2. 둥이 is a kind of suffix which means people who are so quite and lovely. it is noun as well. So we can easily say "귀염둥이" when we see a lovely baby.