Taunts start to trouble moderates (6)
I believe the answer is:
teases
'taunts' is the definition.
('tease' can be a synonym of 'taunt')
'start to trouble moderates' is the wordplay.
'start to' indicates taking the first letters.
'moderates' becomes 'eases' (moderate can mean to ease or relieve).
The first letter of 'trouble' is 't'.
't'+'eases'='TEASES'
(Other definitions for teases that I've seen before include "Annoys playfully" , "Banters, pulls leg" , "Attempts to provoke through persistent annoyance" , "Provokes in playful manner" , "is tantalising" .)