If you lose it you may slip - into the red? (7)
I believe the answer is:
balance
'red?' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for balance that I've seen before include "Libra - amount in account" , "Scale for weighing" , "Weighing apparatus" , "Rest" , "Equilibrium or steady position" .)