tooth (n.) Look up tooth at Dictionary.comOld English toð (plural teð), from Proto-Germanic *tan-thuz (cognates: Old Saxon, Danish, Swedish, Dutch tand, Old Norse tönn, Old Frisian toth, Old High German zand, German Zahn, Gothic tunþus), from PIE *dent- "tooth" (cognates: Sanskrit danta, Greek odontos, Latin dens, Lithuanian dantis, Old Irish det, Welsh dent).
night (n.) Look up night at Dictionary.comOld English niht (West Saxon neaht, Anglian næht, neht) "night, darkness;" the vowel indicating that the modern word derives from oblique cases (genitive nihte, dative niht), from Proto-Germanic *nakht- (cognates: Old Saxon and Old High German naht, Old Frisian and Dutch nacht, German Nacht, Old Norse natt, Gothic nahts).
The Germanic words are from PIE *nekwt- "night" (cognates: Greek nuks "a night," Latin nox, Old Irish nochd, Sanskrit naktam "at night," Lithuanian naktis "night," Old Church Slavonic nosti, Russian noch', Welsh henoid "tonight"), according to Watkins, probably from a verbal root *neg- "to be dark, be night."
knee (n.) Look up knee at Dictionary.comOld English cneo, cneow "knee," from Proto-Germanic *knewam (cognates: Old Norse kne, Old Saxon kneo, Old Frisian kni, Middle Dutch cnie, Dutch knie, Old High German kniu, German Knie, Gothic kniu), from PIE root *g(e)neu- (cognates: Sanskrit janu, Avestan znum, Hittite genu "knee;" Greek gony "knee," gonia "corner, angle;" Latin genu "knee").
super- Look up super- at Dictionary.comword-forming element meaning "above, over, beyond," from Latin super-, from adverb and preposition super "above, over, on the top (of), beyond, besides, in addition to," from *(s)uper-, variant form of PIE *uper "over" (cognates: Sanskrit upari, Avestan upairi "over, above, beyond," Greek hyper, Old English ofer "over," Gothic ufaro "over, across," Gaulish ver-, Old Irish for), comparative of root *upo "under" (see sub-). In English words from Old French, it appears as sur-. The primary sense seems to have shifted over time from usually meaning "beyond" to usually meaning "very much," which can be contradictory. E.g. supersexual, which is attested from 1895 as "transcending sexuality," from 1968 as "very sexual."
star (n.) Look up star at Dictionary.comOld English steorra "star," from Proto-Germanic *sterron, *sternon (cognates: Old Saxon sterro, Old Frisian stera, Dutch ster, Old High German sterro, German Stern, Old Norse stjarna, Swedish stjerna, Danish stierne, Gothic stairno).
This is from PIE *ster- (2) "star" (cognates: Sanskrit star-, Hittite shittar, Greek aster, astron, Latin stella, Breton sterenn, Welsh seren "star"), of uncertain connection to other roots. Some suggest it is from a root meaning "to strew, scatter." 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 žvaigžde, Old Church Slavonic zvezda, Polish gwiazda, Russian zvezda) is not explained.