Average temperature, as intended (5)
I believe the answer is:
meant
'as intended' is the definition.
(I've seen this before)
'average temperature' is the wordplay.
'average' becomes 'mean' (type of average).
'temperature' becomes 't' (abbreviation).
'mean'+'t'='MEANT'
(Other definitions for meant that I've seen before include "Intended, had in mind" , "Had as purpose or design" , "Had as intention or purpose" , "Denoted" , "designed" .)