Dodgy tax rule I use initially offering delight (9)
I believe the answer is:
luxuriate
'delight' is the definition.
Although both the answer and definition are verbs in their base form, I can't see how they can define each other.
'dodgy tax rule i use initially' is the wordplay.
'dodgy' indicates anagramming the letters (a dodgy or wrong order of the letters).
'initially' suggests taking the first letters.
The first letter of 'use' is 'u'.
'tax'+'rule'+'i'+'u'='taxruleiu'
'taxruleiu' anagrammed gives 'LUXURIATE'.
'offering' is the link.
Can you help me to learn more?
(Other definitions for luxuriate that I've seen before include "Indulge oneself" , "Enjoy greatly, to excess perhaps" , "Revel in indulgence" .)