IPA: /ˈruːmiər/
KK: /ˈrumiər/
Having more space than something else; more spacious.
This apartment is roomier than the last one we looked at.
Roomier → It is formed from "room" (from Old English *rum*, meaning space or area) and "-ier" (a comparative suffix indicating more). The word "roomier" means having more space or area compared to something else.
Think of 'room' as representing space, and the '-ier' suffix means more. So, when something is roomier, it simply has more space.