Etymology
Advertisement
interstellar (adj.)
1620s, "situated between or among the stars," in reference to the night sky (modern astronomical sense is from 1670s), from inter- "between" + Latin stella "star" (from PIE root *ster- (2) "star"). Intersiderial in the same sense is from 1650s.
Related entries & more 
Advertisement
*ster- (2)

Proto-Indo-European root meaning "star." Buck and others doubt the old suggestion that it is a borrowing from Akkadian istar "venus." The source of the common Balto-Slavic word for "star" (Lithuanian žvaigždė, Old Church Slavonic zvezda, Polish gwiazda, Russian zvezda) is not explained.

It forms all or part of: aster; asterisk; asterism; asteroid; astral; astro-; astrobiology; astrobleme; astrognosy; astroid; astrolabe; astrolatry; astrology; astromancy; astronaut; astronomy; AstroTurf; constellation; disaster; Estella; Esther; instellation; interstellar; lodestar; star; stardust; starfish; starlet; starlight; starry; stellar; stellate.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit star-; Hittite shittar, Greek aster "star," with derivative astron; Latin stella, Breton sterenn, Welsh seren "star."

Related entries & more 
parsec (n.)

interstellar distance measure, 1913, from first elements of parallax second. It is the distance at which an object has parallax (viewed from Earth at an interval of six months and halved) of one second of arc, or about 3.26 light-years.

Related entries & more