Primarily, intelligence and love combined (2,3)
I believe the answer is:
in one
'combined' is the definition.
(as in 'all in one')
'primarily intelligence and love' is the wordplay.
'primarily' suggests taking the first letters.
'and' says to put letters next to each other.
'love' becomes 'none' (in tennis, 'love' means zero).
The first letter of 'intelligence' is 'i'.
'i'+'none'='IN ONE'
(Other definitions for in one that I've seen before include "A hole . . . . . is a singular golf score" , "united" , "Combined" , "As a single unit" .)