We all have an excellent right to it (3)
I believe the answer is:
air
'we all' is the definition.
I can't tell whether this definition defines the answer.
'an excellent right to it' is the wordplay.
'an excellent' becomes 'ai' (resembles 'A1', old-fashioned term for excellent).
'right' becomes 'r' (abbreviation).
'to it' says to put letters next to each other.
'ai'+'r'='AIR'
'have' acts as a link.
Can you help me to learn more?
(Other definitions for air that I've seen before include "Divulge" , "Ventilate, say grievance" , "Atmosphere, manner" , "Of which 78% is nitrogen" , "Bearing, manner" .)