Survey barely adequate, incomplete (4)
I believe the answer is:
scan
'survey' is the definition.
(I've seen this in another clue)
'barely adequate incomplete' is the wordplay.
'barely adequate' becomes 'scant' (I've seen this in another clue).
'incomplete' means to remove the last letter.
'scant' with its final letter taken away is 'SCAN'.
(Other definitions for scan that I've seen before include "Survey; screen" , "Examine quickly" , "MRI or CAT say" , "Inspect" , "Look briefly through" .)