Advanced and hybrid unlike this clue (6)
I believe the answer is:
across
'unlike this clue' is the definition.
(I've seen this before)
'advanced and hybrid' is the wordplay.
'advanced' becomes 'a'.
'and' means one lot of letters go next to another.
'hybrid' becomes 'cross' (I've seen this before).
'a'+'cross'='ACROSS'
(Other definitions for across that I've seen before include "Clue with solution not going in the direction of this one!" , "From one side to another" , "As this is entered" , "14 of these clues are" , "Towards the other side of" .)