There could be no sense in unity (7)
I believe the answer is:
oneness
'unity' is the definition.
(I know that unity can be written as oneness)
'there could be no sense' is the wordplay.
'there' becomes 'o' (I can't justify this - if you can you should give a lot more credence to this answer).
'could be' indicates anagramming the letters.
'no' becomes 'n' (common abbreviation y/n).
'n'+'sense'='nsense'
'nsense' with letters rearranged gives 'neness'.
'o'+'neness'='ONENESS'
'in' is the link.
Can you help me to learn more?
(Other definitions for oneness that I've seen before include "Singular state" , "Unity" , "Agreement" , "Singular quality" , "#Unique quality" .)