στοιχεῖον

any first thing, from which the others belonging to some series or composite whole take their rise, an element, first principal, the letters of the alphabet as the elements of speech, not however the written characters, but the spoken sounds, the elements from which all things have come, the material causes of the universe, the heavenly bodies, either as parts of the heavens or (as others think) because in them the elements of man, life and destiny were supposed to reside, the elements, rudiments, primary and fundamental principles of any art, science, or discipline, i.e. of mathematics, Euclid's geometry