Temporary authorities on the subject of convenience (7)

I believe the answer is:
regents
'temporary authorities' is the definition.
The definition and answer can be both people as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'the subject of convenience' is the wordplay.
'the subject of' becomes 're' ('re' means regarding or about).
'convenience' becomes 'gents' (I've seen this before).
're'+'gents'='REGENTS'
'on' is the link.
Can you help me to learn more?
(Other definitions for regents that I've seen before include "They rule on behalf of monarchs" , "They have leading roles" .)
