Henry enthralled by Carmen, I see (3)
I believe the answer is:
aha
'i see' is the definition.
(both are said after realising something)
'henry enthralled by carmen' is the wordplay.
'henry' becomes 'H' (symbol for the unit of electrical inductance).
'enthralled by' means one lot of letters goes inside another ('enthral' can mean 'capture').
'carmen' becomes 'aa' (I am not sure about this - if you are sure you should believe this answer much more).
'h' placed inside 'aa' is 'AHA'.
Can you help me to learn more?
(Other definitions for aha that I've seen before include "Bingo" , "Exclamation of triumph or mockery, a palindrome" , "Palindromic exclamation of triumph or surprise" , "I've got it!" , "Cry of surprise" .)