Perfunctory
Definition 1 of 2
Pro Tip 1/3
Emotionless Execution
'Perfunctory' often implies a lack of emotion or interest in performing an action. His handshake was perfunctory and cold.
Pro Tip 2/3
Duty without Zeal
The word suggests someone is doing something out of obligation, not because they want to. He delivered the speech with perfunctory enthusiasm.
Pro Tip 3/3
Minimal Effort
Use 'perfunctory' to describe an action done with the least effort necessary. She cleaned the room in a perfunctory way, missing many spots.