Blocks (4)
'blocks' is the definition.
(barring is a kind of blocking)
This is all the clue.
(Other definitions for bars that I've seen before include "Metal rods or pubs" , "Obstacles" , "See 4" , "Establishments where alcoholic drinks are served" , "Watering holes - units in musical scores" .)
'blocks' is the definition.
(damming is a kind of blocking)
This is the entire clue.
(Another definition for dams that I've seen is " game of draughts".)
'blocks' is the definition.
('cube' can be a synonym of 'block')
This is the entire clue.
(Other definitions for cubes that I've seen before include "Three-dimensional shapes with six sides" , "Solid body with six equal square faces" , "1, 8, 27 etc" , "Geometrical solids" , "Eg, eight, twenty-seven" .)