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.
Best Hand Pruners / Pruning Shears. by Monica Hemingway 18 Comments. Pruners (also called clippers, pruning shears, or secateurs) are used to trim and shape plants, deadhead, prune out dead or damaged foliage and small branches, and cut back perennials. Theyâre one of the most-used gardening tools so itâs important to get a pair that works best for you.