I cant find this word in the korean dictionary. Is this word used often?
I think "노약자석" is more frequently used. There are other words like "임산부석(for pregnant women)", "경로석(for senior citizen)".
Yeah, 노약자석 (老弱者席) is used more commonly. On buses and subway cars you'll usually be able to see both 노약자석 and 임산부석 (임산부 배려석). Most of the time 노약자석 will have an illustration and small written note saying the seat is priority for the elderly and ill, pregnant, disabled or injured, and persons accompanied with child/ren.