Farm animal on a road, chicken (6)
I believe the answer is:
coward
'chicken' is the definition.
(similar in meaning)
'farm animal on a road' is the wordplay.
'farm animal' becomes 'cow' (type of farm animal).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'road' becomes 'rd' (abbreviation for road).
'cow'+'a'+'rd'='COWARD'
(Other definitions for coward that I've seen before include "Person lacking courage" , "Gutless type" , "Yellow-belly" , "whose encounter was briefly filmed" , "Noel . . . . . ., English playwright and actor" .)