/ Dictionary / Index E Einsteinian: Meaning and Definition of Find definitions for: Ein•stein•i•an Pronunciation: (īn-stī'nē-un), [key] — adj. pertaining to Albert Einstein or his theories, esp. the theory of relativity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: einsteinian (Thesaurus) Einstein equation einsteinium Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language