- EosThe Greek goddess of the dawn; daughter of Hyperion and Theia, sister of Helios and Selene, wife of Astraeus (god of the dusk), and mother of the four Anemoi ("Winds"), and the five Astra Planeta ("Wandering Stars/Planets"). Her Roman counterpart is Aurora.
- EoceneOf a geologic epoch within the Paleogene period from about 56 to 34 million years ago.
- eosinA red, acidic dye commonly used in histological stains.
- eo-earliest
- eoanRelating to the dawn.
- eohippusAn extinct early Eocene mammal (Hyracotherium leporinum), ancestral to the modern horse.
- eolithCrudely chopped flints, believed to be naturally produced by geological processes such as glaciation.
- eolithicof or relating to the early period of the Stone Age marked by the use of eoliths.
- eophyteA fossil plant from the Silurian age
- eosphoriteAn orthorhombic-dipyramidal mineral containing aluminum, hydrogen, manganese, oxygen, and phosphorus.