Light inside regularly seen in time before Easter (7)
I believe the answer is:
lenient
'light' is the definition.
(I've seen this before)
'inside regularly seen in time before easter' is the wordplay.
'regularly seen' indicates alternate letters.
'in' means one lot of letters goes inside another.
'time before easter' becomes 'lent'.
The alternating letters of 'inside' are 'nie'.
'nie' placed into 'lent' is 'LENIENT'.
(Other definitions for lenient that I've seen before include "Not severe in punishing" , "Inclined to let people off lightly" , "Compassionate" , "Soft on the rules" , "Tolerant, rather than strict" .)