Punctual (2,4)
'punctual' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for prompt that I've seen before include "Give cue to forgetful actor" , "Precisely on time" , "Reminder" , "Cause; on time" , "Punctual; instigate" .)
'punctual' is the definition.
(being on time is being punctual)
This is the entire clue.
(Other definitions for on time that I've seen before include "Punctual, not late" , "according to schedule" , "promptly" , "(Of train) not late" , "Not running late" .)