It forms all or part of: caca; cachexia; caco-; cacoethes; cacophony; cucking stool; kakistocracy; poppycock.
It is the hypothetical source of/evidence for its existence is provided by: Greek kakke "human excrement," Latin cacare, Irish caccaim, Serbo-Croatian kakati, Armenian k'akor; Old English cac-hus "latrine."
Etymologists dispute whether the modern Germanic words (Dutch kakken, Danish kakke, German kacken), are native cognates or student slang borrowed from Latin cacare. Caca appears in Modern English in slang c. 1870, and could have been taken from any or several of the languages that used it.
*sāwel-, Proto-Indo-European root meaning "the sun." According to Watkins, the *-el- in it originally was a suffix, and there was an alternative form *s(u)wen-, with suffix *-en-, hence the two forms represented by Latin sol, English sun.
It forms all or part of: anthelion; aphelion; girasole; heliacal; helio-; heliotrope; helium; insolate; insolation; parasol; parhelion; perihelion; Sol; solar; solarium; solstice; south; southern; sun; Sunday.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit suryah, Avestan hvar "sun, light, heavens;" Greek hēlios; Latin sol "the sun, sunlight;" Lithuanian saulė, Old Church Slavonic slunice; Gothic sauil, Old English sol "sun;" Old English swegl "sky, heavens, the sun;" Welsh haul, Old Cornish heuul, Breton heol "sun;" Old Irish suil "eye;" Avestan xueng "sun;" Old Irish fur-sunnud "lighting up;" Old English sunne German Sonne, Gothic sunno "the sun."