Hospital worker must be tidy (7)
I believe the answer is:
orderly
This clue is a double definition.
'hospital worker' is the first definition.
(I've seen this before)
'tidy' is the second definition.
(similar in meaning)
'must be' is the link.
(Other definitions for orderly that I've seen before include "Well-behaved; hospital worker" , "Officer's assistant" , "Neat, tidy; soldier" , "Well-behaved -- soldier attending to a superior officer" , "Hospital attendant - neat" .)