Like this clue? (6)
I believe the answer is:
across
'like this clue?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for across that I've seen before include "First word in any crossword" , "what follows one here" , "Transversely" , "written like this?" , "From side to side, like this clue" .)