Five lies about disguises (5)
I believe the answer is:
veils
'disguises' is the definition.
(I've seen this in another clue)
'five lies about' is the wordplay.
'five' becomes 'v' (Roman numeral).
'about' indicates an anagram.
'lies' is an anagram of 'eils'.
'v'+'eils'='VEILS'
(Other definitions for veils that I've seen before include "Covers or partly conceals - bride's face?" , "coverage" , "Masks" , "See 20" , "Garments to cover head and face" .)