In use (8)
'in use' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for operational that I've seen before include "running" , "working satisfactorily?" , "In working order" , "Ready for action" , "Ready for use" .)
'in use' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for occupied that I've seen before include "Lived in" , "Employed" , "at work" , "Filled or in use" , "Captured" .)