An Etymological Dictionary of Astronomy and Astrophysics

Possessing outstanding quality or superior merit; remarkably good (Dictionary.com).

Etymology (EN): M.E., from O.Fr. excellent “outstanding,” from L. excellentem (nominative excellens) “towering, prominent, superior,” pr.p. of excellere “to surpass, be superior,“from → ex- “out from” + cellere “to rise high, tower,” related to celsus “high, great,” from PIE root *kel- “to be elevated; hill;” from which are derived L. collis “hill,” columna “projecting object,” culmen “top, summit,” cellere “raise;” Gk. kolonos “hill,” kolophon “summit;” Lithuanian kalnas “mountain,” kalnelis “hill;” E. hill; Pers. dialects (Gilân) kol, kulâ “hill,” (Dâmqân) kalut, kolut “successive soil hills, hill,” (Tabari) keti “hill,” (Jâsk) kit “hill.”

Etymology (PE): Mid.Pers. pahrom “excellent,” variant pahlom, ultimately from *parθama- “the highest, the most elevated,” literally “Parthian,” adj. from Parθa(va)-; cf. pahlavân “hero,” another similar respect word related to Parthia (Nyberg 1974).