Heartfelt selection of words in ceremony (7)
I believe the answer is:
sincere
'heartfelt' is the definition.
('sincere' can be similar in meaning to 'heartfelt')
'selection of words in ceremony' is the wordplay.
'selection of' says the answer is hidden in the clue.
'SINCERE' is hidden in the letters of 'words in ceremony'.
(Other definitions for sincere that I've seen before include "straightforward" , "Genuine and honest" , "Unaffected" , "'Genuine, not deceitful (7)'" , "Open and genuine, not deceitful" .)