Joiner perhaps earned on a regular basis (3)
I believe the answer is:
and
'joiner' is the definition.
(I've seen this in other clues)
'earned on a regular basis' is the wordplay.
'on a regular basis' means one should take alternating letters.
The alternating letters of 'earned' are 'AND'.
'perhaps' is the link.
(Other definitions for and that I've seen before include "A very common conjunction" , "Joiner or dandies" , "Word to connect" , "Also" , "moreover" .)