Are about to make love (5)
I believe the answer is:
adore
'love' is the definition.
(adoring is a kind of loving)
'are about to' is the wordplay.
'are about' becomes 'a' (abbreviation in Chambers).
'to' becomes 'dore' (I can't explain this - if you can you should give a lot more credence to this answer).
'a'+'dore'='ADORE'
'make' acts as a link.
(Other definitions for adore that I've seen before include "Love to distraction" , "Honour" , "Love, worship" , "Respect deeply" , "Love, revere intensely" .)