Disreputable person is great socially, from time to time (6)
I believe the answer is:
rascal
'disreputable person' is the definition.
'rascal' can be an answer for 'person' (rascal is a kind of person). I am not sure about the 'disreputable' bit.
'great socially from time to time' is the wordplay.
'from time to time' means one should take alternating letters (letters removed on a regular basis).
'great'+'socially'='greatsocially'
The alternating letters of 'greatsocially' are 'RASCAL'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for rascal that I've seen before include "naughty child" , "Brat" , "Mischievous or cheeky child" , "A naughty chap or bold boy" , "not one to be admired" .)