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.
43,560 sq ft per acre. A square mile is defined as 640 acres. A square mile is 5,280 feet x 5,280 feet, for a total of 27,878,400 square feet. Divide that by 640 to get 43,560 square feet in an acre. square mile is 5,280 feet x 5,280 feet, for a total of 27,878,400 square feet. Divide that by 640 to get 43,560 square feet in an acre.