Using 'deign' suggests you think you're lowering yourself to do something not worthy of your status. The celebrity didn't deign to attend the local award ceremony.
Pro Tip 2/3
Rarely Complimentary
'Deign' often implies criticism or sarcasm towards the subject's attitude. He finally deigned to acknowledge the intern's presence.
Pro Tip 3/3
Formal Context
The word 'deign' is formal and best used in writing or formal speech. The professor deigned to consider the alternative theory.