__ jar (3)
'jar' is the definition.
(I know that jar can be written as jolt)
This is all the clue.
(Other definitions for jolt that I've seen before include "Sudden shock" , "elbow" , "Shock, jerk" , "Sudden jerk" , "Jostle; shock" .)
(Other definitions for tip that I've seen before include "The extreme end of insider information?" , "Useful hint; end" , "present!" , "Dump; hint" , "Point of gratuity" .)
(Other definitions for mason that I've seen before include "Jewish comedian" , "Craftsperson who works with stone or brick" , "secretive lodger!" , "One going to work in building" , "Stone carver" .)