Nurse having no time for president (5)

I believe the answer is:

carer

I'm a little stuck... Click here to teach me more about this clue!

'nurse' is the definition.
(medical worker)

I don't understand how the remainder of the clue works.

(Other definitions for carer that I've seen before include "Responsible person" , "One looking after sick" , "One looking after an incapacitated person" , "Raising of a siege; financial assistance" , "One with responsibility for dependent person" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app