Spoken or verbal (4)
I believe the answer is:
oral
This clue is a double definition.
'spoken' is the first definition.
(similar in meaning)
'verbal' is the second definition.
(I've seen this before)
(Other definitions for oral that I've seen before include "By word of mouth (4)" , "Unwritten examination" , "from the trap" , "Said - form of test" , "Mouth-related" .)