Fatty uses cab travelling around Devon regularly (9)
I believe the answer is:
sebaceous
'fatty' is the definition.
(thesaurus)
'uses cab travelling around devon regularly' is the wordplay.
'travelling' indicates anagramming the letters.
'around' means one lot of letters goes inside another.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'devon' are 'eo'.
'uses'+'cab'='usescab'
'usescab' with letters rearranged gives 'sebacus'.
'sebacus' going around 'eo' is 'SEBACEOUS'.
(Other definitions for sebaceous that I've seen before include "Like oily glands in skin" , "Fatty" .)