They represent eleven stages (4)
I believe the answer is:
legs
I believe this clue is a double definition.
'they represent eleven' is the first definition.
(as in 'legs eleven' in bingo)
'stages' is the second definition.
('leg' can be a synonym of 'stage')
(Other definitions for legs that I've seen before include "associated with 11 in game" , "Lower limbs" , "Stages of a journey" , "Members" , "Sections of a journey or course" .)