supererogatory
/ˌsupərəˈrɑɡəˌtɔri/
adjective
- Going beyond what is required or expected; extra and not strictly necessary.
- Adding a handwritten thank-you note to the email was supererogatory but very appreciated.
- Her supererogatory efforts to help the new employee settle in went far beyond her job description.
- The chef's supererogatory garnish made the simple dish look like a work of art.