軽輩[keihai] underling
後輩[kouhai] junior (at work, school, etc.)
若輩者[jakuhaisha] fledgling
先輩[senpai] senior (at work or school)
鼠輩[sohai] small fry

俗輩[zokuhai] worldlings
同年輩[dounenpai] persons of the same age
同年輩の人[dounenpainohito] contemporary
同輩[douhai] fellows
年輩[nenpai] elderly