Photoshop tool (6)
'photoshop tool' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eraser that I've seen before include "Rubber for removing marks" , "(Pencil, ink) rubber" , "A schoolboy's rubber" , "What a poor artist needs" , "Required, should you make a mistake" .)
(Other definitions for crop that I've seen before include "Bird's gullet pouch" , "Yield -- trim" , "Type of whip" , "Short cut - taken when hunting?" , "Yield from a single growing season" .)