Fraternity member described by team as one-dimensional (5)
I believe the answer is:
mason
'fraternity member' is the definition.
(the Freemasons are a fraternal society)
'described by team as one-dimensional' is the wordplay.
'described by' indicates the answer is hidden within the clue.
'MASON' is hidden in the letters of 'team as one dimensional'.
(Other definitions for mason that I've seen before include "Jewish comedian" , "Secret society member" , "Stone-worker" , "Stone carver" , "One in lodge" .)