Mask, very intriguingly, slipping on rogue initially (5)
I believe the answer is:
visor
'mask' is the definition.
(thesaurus)
'very intriguingly slipping on rogue initially' is the wordplay.
'very' becomes 'v' (abbreviation).
'initially' suggests taking the first letters.
The first letters of 'intriguingly slipping on rogue' is 'isor'.
'v'+'isor'='VISOR'
(Other definitions for visor that I've seen before include "One protecting" , "Face-protector" , "Eye shield" , "Mask" , "Eye protector" .)