adjective
(formal or literary) Of or relating to the earth; (specifically, chiefly science fiction) inhabiting planet Earth as opposed to other planets.
(astronomy) Of a planet, being composed primarily of silicate rocks or metals; see also terrestrial planet.
(mineralogy) Of a mineral: containing tellurium.
noun
(astronomy, historical) Alternative spelling of tellurion (“instrument used to show how the rotation of the Earth on its axis and its orbit around the Sun cause day and night and the seasons”).
(chiefly science fiction) Alternative letter-case form of Tellurian (“inhabitant of the planet Earth”).