Oratory demonstrated by rector, I suspect, capturing hearts (8)
I believe the answer is:
rhetoric
'oratory' is the definition.
(rhetoric is a kind of oratory)
'rector i suspect capturing hearts' is the wordplay.
'suspect' is an anagram indicator.
'capturing' means one lot of letters goes inside another.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'rector'+'i'='rectori'
'rectori' anagrammed gives 'retoric'.
'retoric' placed around 'h' is 'RHETORIC'.
'demonstrated by' acts as a link.
(Other definitions for rhetoric that I've seen before include "Grandiose (insincere) discourse" , "Art of using language for persuasion" , "Impressive or exaggerated speech as in public" , "The art of using words impressively" , "Eloquence" .)