equilateral(n = noun.shape) - a figure whose sides are all equal;
is a kind of figure
equilateral(s = adj.all) - having all sides or faces equal;
Having all the sides equal; as, an equilateral triangle; an equilateral polygon. [1913 Webster]
A side exactly corresponding, or equal, to others; also, a figure of equal sides. [1913 Webster]
equilateral, adj. having all its sides equal in length.