Proto-Indo-European root meaning "winter." 

It forms all or part of: chimera; chiono-; hiemal; hibernacle; hibernal; hibernate; hibernation; Himalaya.

It is the hypothetical source of/evidence for its existence is provided by:  Sanskrit heman "in winter;" Hittite gimmant-, Armenian jmern, Greek kheima, Latin hiems, Old Church Slavonic zima, Lithuanian žiema "winter;" Greek khion "snow."

Proto-Indo-European root meaning "branch, root."

It forms all or part of: deracinate; eradicate; eradication; irradicable; licorice; radical; radicant; radicle; radicular; radish; ramada; ramify; ramus; rhizoid; rhizome; rhizophagous; root; rutabaga; wort.

It is the hypothetical source of/evidence for its existence is provided by: Greek rhiza, Lesbian brisda "root," Greek hradamnos "branch;" Latin radix) "root, radish;" Gothic waurts, Old English wyrt; Welsh gwraidd, Old Irish fren "root."

Proto-Indo-European root meaning "bone."

It forms all or part of: osseous; ossicle; ossuary; ossifrage; ossify; osteo-; osteology; osteopathy; ostracism; ostracize; oyster; periosteum.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit asthi, Hittite hashtai-, Greek osteon "bone," Greek ostrakon "oyster shell," Avestan ascu- "shinbone," Latin os (genitive ossis) "bone," osseus "bony, of bone," Welsh asgwrn, Armenian oskr, Albanian asht "bone."

Proto-Indo-European root meaning "to shine; white," hence "silver" as the shining or white metal.

It forms all or part of: argent; Argentina; argentine; Argo; argue; Argus; hydrargyrum; litharge.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit rajata-, Avestan erezata-, Old Persian ardata-, Armenian arcat, Greek arguron, Latin argentum, Old Irish argat, Breton arc'hant "silver;" Sanskrit arjuna- "white, shining;" Hittite harki- "white;" Greek argos "white."

Proto-Indo-European root meaning "red, ruddy." The only color for which a definite common PIE root word has been found. The initial -e- in the Greek word is because Greek tends to avoid beginning words with -r-.

It forms all or part of: bilirubin; corroborate; Eritrea; erysipelas; erythema; erythro-; Radnor; red; redskin; roan; robust; rooibos; Rotwelsch; rouge; roux; rowan; rubella; rubicund; rubric; ruby; ruddock; ruddy; rufous; Rufus; russet; rust.

It is the hypothetical source of/evidence for its existence is provided by: Latin ruber, also dialectal rufus "light red," mostly of hair; Greek erythros; Sanskrit rudhira-; Avestan raoidita-; Old Church Slavonic rudru, Polish rumiany, Russian rumjanyj "flushed, red," of complexions, etc.; Lithuanian raudas; Old Irish ruad, Welsh rhudd, Breton ruz "red."

Proto-Indo-European root meaning "death." It forms all or part of: innocent; innocuous; internecine; necro-; necropolis; necrosis; necromancy; nectar; nectarine; nociceptive; nocuous; noxious; nuisance; obnoxious; pernicious.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nasyati "disappears, perishes," Avestan nasyeiti "disappears," nasu- "corpse," Old Persian vi-nathayatiy "he injures;" Greek nekros "corpse;" Latin nex, genitive necis "violent death, murder" (as opposed to mors), nocere "to harm, hurt," noxius "harmful;" Greek nekus "dead" (adj.), nekros "dead body, corpse;" Old Irish ec, Breton ankou, Welsh angeu "death."

Proto-Indo-European root meaning "to taste; to choose." It forms words for "taste" in Greek and Latin, but its descendants in Germanic and Celtic mostly mean "try" or "choose." The semantic development could have been in either direction.

It forms all or part of: Angus; choice; choose; degustation; disgust; Fergus; gustation; gustatory; gusto; ragout; Valkyrie.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit jus- "enjoy, be pleased;" Avestan zaosa- "pleasure," Old Persian dauš- "enjoy;" Greek geuesthai "to taste;" Latin gustare "to taste, take a little of;" Old English cosan, cesan, Gothic kausjan "to test, to taste of," Old High German koston "try," German kosten "taste of."

Proto-Indo-European root meaning "to see."

It forms all or part of: amblyopia; antique; antler; atrocity; autopsy; binocle; binocular; biopsy; catoptric; Cyclops; daisy; enoptomancy; eye; eyelet; ferocity; hyperopia; inoculate; inveigle; monocle; monocular; myopia; necropsy; ocular; oculist; oculus; oeillade; ogle; ophthalmo-; optic; optician; optics; optometry; panoptic; panopticon; Peloponnesus; pinochle; presbyopia; prosopopeia; stereoptican; synopsis; triceratops; ullage; wall-eyed; window.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit akshi "the eye; the number two," Greek osse "(two) eyes," opsis "a sight;" Old Church Slavonic oko, Lithuanian akis, Latin oculus, Greek okkos, Tocharian ak, ek, Armenian akn "eye."

Proto-Indo-European root meaning "false, bad, wrong." The exact sense of the root remains uncertain, "since it concerns a collection of largely isolated words in different IE branches" [de Vaan].

It forms all or part of: blame; blaspheme; blasphemous; blasphemy; ‌‌dismal; mal-; malady; malaise; malaria; malediction; malefactor; malefic; malevolence; malevolent; malice; malicious; malign; malison; malversation; mauvais.

It is the hypothetical source of/evidence for its existence is provided by: Avestan mairiia‑, "treacherous;" Greek meleos "idle; unhappy;" Latin male (adv.) "badly," malus (adj.) "bad, evil;" Old Irish mell "destruction;" Armenian mel "sin;" Lithuanian melas "lie," Latvian malds "mistake," possbily also Greek blasphemein "to slander." 

*snā-, Proto-Indo-European root meaning "to swim," with extended form *(s)nāu- "to swim, flow; to let flow," hence "to suckle."

It forms all or part of: naiad; natant; natation; natatorial; natatorium; nekton; nourish; nurse; nursery; nurture; nutrient; nutriment; nutrition; nutritious; nutritive; supernatant.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit snati "bathes," snauti "she drips, gives milk;" Avestan snayeite "washes, cleans;" Armenian nay "wet, liquid;" Greek notios "wet, damp," Greek nan "I flow," nekhein "to swim;" Latin nare "to swim," natator "swimmer;" Middle Irish snaim "I swim," snam "a swimming."