Ignore my amatory larking, it does come from the heart (5)
I believe the answer is:
aorta
'heart' is the definition.
The answer and definition can be both body parts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'ignore my amatory larking it does come from' is the wordplay.
I cannot really understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found in the answer.
'from' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
The remaining letters 'ara' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'the' acts as a link.
Can you help me to learn more?
(Other definitions for aorta that I've seen before include "Main human artery" , "Large blood-vessel" , "Main artery of body" , "This carries blood from the heart" , "Large artery of the heart" .)