Definition of PLACOID. : of, relating to, or being a scale of dermal origin with an enamel-tipped spine characteristic of the elasmobranchs. ADVERTISEMENT.Greek plak-, plax flat surface.First Known Use: 1842.efinition of PLACOID. : of, relating to, or being a scale of dermal origin with an enamel-tipped spine characteristic of the elasmobranchs. ADVERTISEMENT. Greek plak-, plax flat surface. First Known Use: 1842.
A tree pruner is a class 1 lever. The fulcrum is where the two blades cross, and the load is what you are cutting. The effort is applied to the two handles.
A pole pruner is a tool with sharp blades that enables you to cut branches overhead to 12 feet or more without needing a ladder. Proper use of a pole pruner includes knowing how to operate the string, and makes quick work of trimming trees and shrubs. Put on safety glasses for protection from falling leaves and bark.