Einstein
biographical name
Ein·stein ˈīn-ˌstīn 
Albert 1879–1955 American (German-born) physicist
Einsteinian
īn-ˈstī-nē-ən
adjective 
Medical Definition
einstein
noun
ein·stein ˈīn-ˌstīn
: the radiant energy of a given frequency required to effect the complete photochemical transformation of one mole of a photosensitive substance being equal to about 0.004 erg second times the frequency in question