State as indicated by sum of exponents; more particularly,
   the degree of a term is indicated by the sum of the exponents of its
   literal factors; thus, a2b3c is a term of the sixth degree. The degree
   of a power, or radical, is denoted by its index, that of an equation by
   the greatest sum of the exponents of the unknown quantities in any
   term; thus, ax4 + bx2 = c, and mx2y2 + nyx = p, are both equations of
   the fourth degree.