Boost fixed green issues, occasionally (8)
I believe the answer is:
energise
'boost' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how one could define the other.
'fixed green issues occasionally' is the wordplay.
'fixed' indicates anagramming the letters.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
The alternate letters of 'issues' are 'ise'.
'green' with letters rearranged gives 'energ'.
'energ'+'ise'='ENERGISE'
Can you help me to learn more?
(Other definitions for energise that I've seen before include "Give power to" , "Activate" , "Give vitality to" , "Give active force" , "To banish inertia" .)