Override available study (8)
I believe the answer is:
outweigh
'override' is the definition.
(I've seen this before)
'available study' is the wordplay.
'available' becomes 'out' (as in a product which is out).
'study' becomes 'weigh' (I am not sure about this - if you are sure you should believe this answer much more).
'out'+'weigh'='OUTWEIGH'
Can you help me to learn more?
(Other definitions for outweigh that I've seen before include "Be more important or heavier than" , "trump?" , "Preponderate" , "Be heavier than (something)" , "Be greater or more significant than" .)