Surreptitious and quite lacking in attitude (3)
I believe the answer is:
fly
'surreptitious' is the definition.
(fly can mean crafty or surreptitious)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for fly that I've seen before include "Insect; rush" , "Cunning; insect" , "Fishing insect" , "Aviate" , "needs to get away" .)