Eleanor Roosevelt

The International Organization for Standardization country code for Eritrea

Elizabeth Regina, Latin for Queen Elizabeth (plus other monarchs whose name begins with 'E' — latin for "king" is Rex)

ER (TV series), a popular NBC medical drama set primarily in an emergency room

Emergency room, more properly known as the emergency department, a hospital department that treats mainly acute life-threatening injuries and conditions

The symbol for the chemical element, Erbium

Estrogen receptor, a receptor in molecular biology that is activated by estrogen

Equine Exertional Rhabdomyolysis, a syndrome that causes the degeneration of muscle tissue in horses

Er, the main character of the Myth of Er told by Plato in the Republic

Endoplasmic reticulum, an organelle found in cells

Entity-relationship model, a high-level conceptual data model

Edgar Rentería, a baseball player

Relative static permittivity may be represented as <math>\epsilon_r</math>

An earned run in baseball

The International Air Transport Association code for Astar Air Cargo

E/R, an unsuccessful 1980s sitcom

Evidential Reasoning Approach, used during Multi-Criteria Decision Analysis under uncertainty

Er (Biblical name), a name found in the Bible

The suffix -er used in creating a comparative adjective or adverb (e.g., smaller)

A filler word used in dialogue displaying uncertainty

Er (Cyrillic), a letter in the Cyrillic alphabet

Extended Range, a term for missles or planes capable of travelling long distances

The Chico Enterprise-Record, a daily newspaper of Chico, California

Eesti Rahvusringhääling - The Public Service Radio organisation in Estonia