Regularly seen Friends on repeat (4)
I believe the answer is:
redo
'repeat' is the definition.
(thesaurus)
'regularly seen friends on' is the wordplay.
'regularly seen' means one should take alternating letters.
'friends'+'on'='friendson'
The alternate letters of 'friendson' are 'REDO'.
(Other definitions for redo that I've seen before include "Perform (action) again" , "Have second thoughts" , "Make anew" , "Start again" , "Carry out again" .)