Definition of blister. 1  1 : a fluid-filled elevation of the epidermis â compare water blister. 2  2 : an enclosed raised spot (as in paint) resembling a blister. 3  3 : an agent (such as lewisite) that causes blistering. 4  4 : a fungal disease of plants marked by raised patches on the leaves.
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about 4,047 square metres (0.405 hectares) (see below). While all modern variants of the acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends on which yard it is based.
How Many Square Feet in an Acre. Aug 31, 2011 It is easy to imagine an area of one square foot1. In fact, it is a square which has sides of one foot. But many people have problems with visualizing an acre2, to say nothing of converting square feet to acres. There is a good analogy that helps to envision an acre. It is known that a football field is a bit bigger than one acre.