Henry swallowed strong emotion (4)
I believe the answer is:
hate
'strong emotion' is the definition.
(hate is a strong or intense emotion)
'henry swallowed' is the wordplay.
'henry' becomes 'H' (symbol for the unit of electrical inductance).
'swallowed' becomes 'ate'.
'h'+'ate'='HATE'
(Other definitions for hate that I've seen before include "[OPPOSITE OF] Be besotted with" , "Intense dislike" , "Odium" , "Fury" , "Loathing" .)