Hack admitted to dance of seven veils (8)
I believe the answer is:
envelops
'veils' is the definition.
(envelop can mean to cover up or veil)
'hack admitted to dance of seven' is the wordplay.
'hack' becomes 'lop' (I've seen this before).
'admitted to' indicates putting letters inside.
'dance of' indicates anagramming the letters (I've seen 'dancing' mean this).
'seven' is an anagram of 'enves'.
'lop' placed inside 'enves' is 'ENVELOPS'.
(Other definitions for envelops that I've seen before include "Wraps up, covers on all sides" , "Hides" , "Covers on all sides, say as mist does" , "Encloses or enfolds completely" , "surrounds" .)