Insecure, unloved dog? (3)
I believe the answer is:
cur
This clue could be a double definition.
'insecure' is the first definition.
(in the letters 'seCURe')
'unloved dog?' is the second definition.
'cur' can be an answer for 'dog?' (both can mean a despicable person). I'm not sure about the 'unloved' bit.
Can you help me to learn more?
(Other definitions for cur that I've seen before include "Mongrel - coward" , "A low worthless dog" , "Aggressive dog" , "Surly dog (or person)" , "Vile dog" .)