The employees sat around being very noisy (5)
I believe the answer is:
staff
'the employees' is the definition.
(thesaurus)
'sat around being very noisy' is the wordplay.
'around' indicates an anagram.
'being very noisy' becomes 'ff'.
'sat' anagrammed gives 'sta'.
'sta'+'ff'='STAFF'
(Other definitions for staff that I've seen before include "Man" , "Take a rod to the personnel?" , "Stick of authority" , "Body of teachers" , "Post - office workers" .)