Fellows of convenience (5)
I believe the answer is:
gents
I believe this is a double definition.
'fellows' is the first definition.
('gent' can be a synonym of 'fellow')
'convenience' is the second definition.
(I've seen this before)
'of' is the link.
(Other definitions for gents that I've seen before include "Public convenience" , "toilet" , "Men (colloq.)" , "Male loos" .)