Ë definition

(1) The 5th letter of the Roman alphabet

(2) The base of the natural system of logarithms; approximately equal to 2.718282...

(3) The cardinal compass point that is at 90 degrees

(4) A radioactive transuranic element produced by bombarding plutonium with neutrons

(5) A fat-soluble vitamin that is essential for normal reproduction; an important antioxidant that neutralizes free radicals in the body