Attach small light when confused (6)
I believe the answer is:
addled
'confused' is the definition.
(addling is a kind of confusing)
'attach small light' is the wordplay.
'attach' becomes 'add' (I've seen this in another clue).
'small light' becomes 'led' (light emitting diode).
'add'+'led'='ADDLED'
'when' acts as a link.
(Other definitions for addled that I've seen before include "became rotten" , "(Of an egg) went bad" , "Of egg, rotten and producing no chick" , "Scatterbrained like bad egg" , "Confused like rotten egg" .)