primary duty
noun phraseUK /ˈpraɪ.mə.ri ˈdjuː.ti/
US /ˈpraɪ.mɛr.i ˈduː.ti/
The most important job you have to do.
A nurse's primary duty is to take care of patients.
RELATED WORDS
OTHER MEANINGS
2. The first or main thing a person is expected to do at work.
The guard's primary duty is to keep the building safe.
3. The most basic job of a machine or tool.
The primary duty of a lamp is to give light.
4. The main job someone must do before anything else.
Her primary duty as a big sister is to look after her brother.