Reflect - not the first time - and intervene (7)
I believe the answer is:
mediate
'intervene' is the definition.
(I've seen this before)
'reflect not the first time' is the wordplay.
'reflect' becomes 'meditate' (synonyms).
'not' indicates named letters should be taken away.
'the first time' becomes 't' (1st letter of 'time').
'meditate' with 't' taken out is 'MEDIATE'.
'and' acts as a link.
(Other definitions for mediate that I've seen before include "ie Tamed (anag.)" , "try to resolve dispute" , "Umpire has to" , "Arbitrate between parties in dispute" , "Intercede" .)