Sorry, I don't know the clue- can you tell it us please?
My guess would be something to do with railway (abbreviated in crosswords to RY) and West (does clue refer to Mae?)
Wife joins railway head in sardonic style (6) I had W?YS?, ; know that w = wife; "ry" = railway; and "wry" means sardonic; but where's the head bit come in?
Wryness would be perfect if it was 7 letters but two posters (this one and peanut246) have both said it's only got 6 letters.
I prefer WRYISH to WRYEST byt can't fully explain either