We all need it, with excellent right (3)
I believe the answer is:
air
'we all need it' is the definition.
I can't tell whether this defines the answer.
'with excellent right' is the wordplay.
'with' means one lot of letters go next to another.
'excellent' becomes 'ai' (resembles 'A1', old-fashioned term for excellent).
'right' becomes 'r' (abbreviation).
'ai'+'r' is 'AIR'.
Can you help me to learn more?
(Other definitions for air that I've seen before include "Gas mix surrounding the earth" , "The earth's atmosphere" , "Ventilate with breathing gas" , "Atmosphere surrounding us" , "Ventilate, say grievance" .)