Words related to *segh-
also callisthenics, kind of light gymnastics, 1842, (the adjective calisthenic/callisthenic, of exercises, was in use by 1837), formed on model of French callisthenie, from Latinized combining form of Greek kallos "beauty" (see Callisto) + sthenos "strength, power, ability, might" (perhaps from PIE root *segh- "to have, hold," on the notion of "steadfastness, toughness") + -ics.
"Of this at least I am certain, that none but a born romp and hoyden, or a girl accustomed [to] those new-fangled pulleyhauley exercises, the Calisthenics, is fitted for the boisterous evolutions of a sea-voyage." [Thomas Hood, "The Schoolmistress Abroad," New Monthly Magazine, 1842]
Originally, gymnastic exercises suitable for girls and meant to develop the figure and promote graceful movement. OED describes the word as "chiefly a term of young ladies' boarding-schools." A place for doing it was a calisthenium (1853). The proper Greek, if there was such a word in Greek, would have been *kallistheneia.
"castrated man," late 14c., eunuk, from Latin eunuchus, from Greek eunoukhos "castrated man," originally "guard of the bedchamber or harem," from euno-, combining form of eune "bed," a word of unknown origin, + -okhos, from stem of ekhein "to have, hold" (from PIE root *segh- "to hold").
Eunuches is he þat is i-gilded, and suche were somtyme i-made wardeynes of ladyes in Egipt. [Ranulph Higden’s "Polychronicon," mid-14c., John Trevisa's translation, 1380s]
Harem attendants in Oriental courts and under the Roman emperors were charged with important affairs of state. The Greek and Latin forms of the word were used in the sense "castrated man" in the Bible but also to translate Hebrew saris, which sometimes meant merely "palace official," in Septuagint and Vulgate, probably without an intended comment on the qualities of bureaucrats. Related: Eunuchal; eunuchry; eunuchize.