Extol the virtues of (4)
I believe the answer is:
tout
'extol the virtues of' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tout that I've seen before include "Profiteering ticket seller" , "Solicit, canvass" , "Ticket profiteer" , "Reseller of tickets at a profit" , "Solicit(or)" .)