Fellow in train organising cover (9)
I believe the answer is:
tarpaulin
'cover' is the definition.
(I know that tarpaulin is a type of cover)
'fellow in train organising' is the wordplay.
'fellow' becomes 'paul' (I've seen this before).
'in' is an insertion indicator.
'organising' indicates anagramming the letters.
'train' with letters rearranged gives 'tarin'.
'paul' placed into 'tarin' is 'TARPAULIN'.
(Other definitions for tarpaulin that I've seen before include "sailor's hat" , "Waterproofed canvas" , "Waterproof cloth" , "Waterproof canvas used as covering" , "[SHHET]" .)