Character in love on Titanic (5)
I believe the answer is:
omega
'character' is the definition.
(omega is a kind of letter of the alphabet)
'love on titanic' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'on titanic' becomes 'mega' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'o'+'mega'='OMEGA'
'in' is the link.
Can you help me to learn more?
(Other definitions for omega that I've seen before include "Final Greek letter" , "Final outcome" , "Foreign character" , "Greek long 'o'" , "Ending of a series or sequence" .)