Appraisal fools people in street (10)
I believe the answer is:
assessment
'appraisal' is the definition.
(I know that appraisal can be written as assessment)
'fools people in street' is the wordplay.
'fools' becomes 'asses' (ass can mean a foolish person).
'people' becomes 'men' (men are people).
'in' is an insertion indicator.
'street' becomes 'st' (abbreviation).
'men' put within 'st' is 'sment'.
'asses'+'sment'='ASSESSMENT'
(Other definitions for assessment that I've seen before include "rating" , "Evaluation, estimation" , "Survey" , "amount to be paid" , "Appraisal" .)