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.
Submit. Red maple, known botanically as Acer rubrum, is a species of deciduous tree know for its rich red fall foliage. There are numerous cultivars that vary from leaf shape and size to exact hue of fall foliage.ubmit. Red maple, known botanically as Acer rubrum, is a species of deciduous tree know for its rich red fall foliage. There are numerous cultivars that vary from leaf shape and size to exact hue of fall foliage.