Carers of the sick (6)
I believe the answer is:
nurses
'carers of the sick' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nurses that I've seen before include "Cares for the sick." , "They tend the sick" , "workers in colonies" , "Cares for during illness" , "They take care of the sick" .)