Angel (6)
'angel' is the definition.
(I know that cherub is a type of angel)
This is all the clue.
(Other definitions for cherub that I've seen before include "A heavenly winged babe" , "goody-goody?" , "innocent young thing" , "Angelic infant" , "Angel portrayed as a winged child" .)
'angel' is the definition.
(I know that Seraph is a type of angel)
This is the entire clue.
(Other definitions for seraph that I've seen before include "Heavenly creature" , "Angelic character" , "Leading angel" , "Angel with winged head of child" , "Angel of highest order" .)
(Other definitions for heart that I've seen before include "Vital organ - centre - courage" , "show enthusiasm" , "Muscular organ - compassion" , "Muscular organ for blood circulation" , "See 22" .)