- Ⅰ.E  (also e) ► NOUN (pl. Es or E's) 1) the fifth letter of the alphabet. 2) denoting the fifth in a set. 3) Music the third note of the diatonic scale of C major.Ⅱ.E  ► ABBREVIATION 1) East or Eastern. 2) informal the drug Ecstasy or a tablet of Ecstasy. 3) Physics energy. 4) denoting products, in particular food additives, which comply with EU regulations.
English terms dictionary. 2015.