Wax lyrical about the former lot brought back (5)
I believe the answer is:
extol
'wax lyrical about' is the definition.
(I've seen this in another clue)
'former lot brought back' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'brought back' is a reversal indicator.
'lot' backwards is 'tol'.
'ex'+'tol'='EXTOL'
'the' acts as a link.
(Other definitions for extol that I've seen before include "Praise highly, laud" , "Sing the praises of" , "Praise with enthusiasm" , "Exalt" , "Applaud" .)