Exaggerate about medium dog that's really small (4,2)
I believe the answer is:
camp up
'really small' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'exaggerate about medium dog' is the wordplay.
I cannot really see how this works, but
'about' could be 'ca' (circa) and 'ca' is found in the answer.
'medium' could be 'm' (as in UK clothing sizes) and 'm' is found within the answer.
'dog' could be 'pup' (I have seen 'Young dog ' mean 'pup' so perhaps 'dog' could also mean 'pup') and 'pup' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'that's' acts as a link.
Can you help me to learn more?