Hastened to adopt disguise for auditors (4)
I believe the answer is:
hied
'hastened' is the definition.
(hie could historically mean to go quickly)
'to adopt disguise for auditors' is the wordplay.
'to adopt disguise' becomes 'hide' (to hide oneself).
'for auditors' indicates a 'sounds like' (homophone) clue (auditor can mean someone listening).
'hide' is a homophone of 'HIED'.
(Other definitions for hied that I've seen before include "Hastened" , "Went quickly (archaic)" , "Hurried" , "Ran" , "Rushed" .)