Dotted line instruction (4)
I believe the answer is:
tear
'dotted line instruction' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tear that I've seen before include "Rend; travel in haste" , "Move quickly; pull apart" , "Product of the lachrymal gland" , "Droplet; rip" , "'A rip, binge or drop of saline solution (4)'" .)