Express disapproval about a medic supplying grass! (6)
I believe the answer is:
bamboo
'grass' is the definition.
(thesaurus)
'express disapproval about a medic' is the wordplay.
'express disapproval' becomes 'boo' (I've seen this before).
'about' indicates putting letters inside.
'medic' becomes 'mb' (Bachelor of Medicine).
'a'+'mb'='amb'
'boo' going around 'amb' is 'BAMBOO'.
'supplying' is the link.
(Other definitions for bamboo that I've seen before include "Heavy tropical cane used in furniture" , "Thick tropical cane" , "Tropical grass with strong hollow stems" , "stick" , "Spotted tile; carnival mask" .)