Source : Webster's Revised Unabridged Dictionary (1913)

Foursquare \Four"square`\, a.
   Having four sides and four equal angles. --Sir W. Raleigh.

Source : WordNet®

foursquare
     adj : characterized by firm and unwavering conviction; "a
           foursquare refusal to yield"
     n : (geometry) a plane rectangle with four equal sides and four
         right angles; a four-sided regular polygon; "you can
         compute the area of a square if you know the length of
         its sides" [syn: {square}]
     adv 1: in a square position; "the building stood foursquare"
     2: with firmness and conviction; without compromise; "he stood
        foursquare for religious liberty and toleration"-
        C.G.Bowers; "dealt straightforwardly with all issues"
        [syn: {squarely}, {straightforwardly}]