Continuing to annoy Heather after row (8)
I believe the answer is:
rankling
'continuing to annoy' is the definition.
I can't tell whether this definition defines the answer.
'heather after row' is the wordplay.
'heather' becomes 'ling' (synonyms).
'after' is a charade indicator (letters next to each other).
'row' becomes 'rank' (as in a taxi rank).
'ling' after 'rank' is 'RANKLING'.
Can you help me to learn more?
(Other definitions for rankling that I've seen before include "leaving a nasty taste in one's mouth" , "causing some bitterness" , "Grating, irritating" , "Causing endless annoyance" , "getting up one's nose" .)