Analyse (8)
(Other definitions for evaluate that I've seen before include "'Assess, appraise (8)'" , "Make an assessment of, measure" , "Judge the worth of something" , "Make an assessment of, determine worth" , "Reckon worth of" .)
'analyse' is the definition.
(I know that analyse can be written as study)
This is the entire clue.
(Other definitions for study that I've seen before include "Dusty (anag.)" , "Small office" , "Contemplate" , "See 11" , "Den; closely look at" .)