what is lathing
Full Definition of LATH. 1. : a thin narrow strip of wood nailed to rafters, joists, or studding as a groundwork for slates, tiles, or plaster. 2. : a building material in sheets used as a base for plaster.3. : a quantity of laths. â lath transitive verb. a long and thin piece of wood that is used in walls and ceilings to support plaster, tiles, etc. plural laths or lath.