late 14c., "pleasantly, enjoyably," from comfortable + -ly (2). Meaning "in a state of comfort" is 1630s.
he works comfortably on three continents
she could have been lying comfortably in bed getting the same relief
she has been able to live comfortably since her husband died
cometh
comeuppance
comfit
comfort
comfortable
comfortably
comforter
comfortless
comfy
comic
comical