PhD travels around the east in April selling material (6)
I believe the answer is:
draper
'selling material' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'phd travels around the east in april' is the wordplay.
'phd' becomes 'rd' (I am not sure about this - if you are sure you should believe this answer much more).
'travels around' says the letters should be written in reverse (turned around).
'the east' becomes 'E' (abbreviation).
'in' means one lot of letters goes inside another.
'april' becomes 'apr' (abbreviation for April).
'rd' back-to-front is 'dr'.
'e' going within 'apr' is 'aper'.
'dr'+'aper'='DRAPER'
Can you help me to learn more?
(Other definitions for draper that I've seen before include "Seller of cloth" , "Dealer in fabrics and sewing materials" , "Seller of textiles" , "Dealer in fabric and haberdashery" , "source of material?" .)