One left Lycra shifts that can be waxed (7)
I believe the answer is:
lyrical
'that can be waxed' is the definition.
(as in waxing lyrical)
'one left lycra shifts' is the wordplay.
'one' becomes 'I' (Roman numeral).
'left' becomes 'l' (common abbreviation).
'shifts' indicates anagramming the letters.
'i'+'l'+'lycra'='illycra'
'illycra' anagrammed gives 'LYRICAL'.
(Other definitions for lyrical that I've seen before include "To wax - is to enthuse" , "Using poetic language, wax thus (7)" , "Enthusiastic - expressing the writer's feelings" , "Using poetic or song-like language" , "In poetic words, song-like" .)