Questionnaire makes us very confused (6)
I believe the answer is:
survey
'questionnaire' is the definition.
(I've seen this before)
'makes us very confused' is the wordplay.
'makes' is an anagram indicator.
'confused' indicates anagramming the letters.
'us' anagrammed gives 'su'.
'very' with letters rearranged gives 'rvey'.
'su'+'rvey'='SURVEY'
(Other definitions for survey that I've seen before include "Overview" , "Thoroughly examine" , "Scan and appraise" , "(Report of) examination of building" , "Look over carefully or inspect" .)