*pel- 1

Proto-Indo-European root meaning "pale."

It forms all or part of: appall; falcon; fallow (adj.) "pale yellow, brownish yellow;" Fauvist; Lloyd; pale (adj.); pallid; pallor; palomino; Peloponnesus; polio; poliomyelitis.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit palitah "gray," panduh "whitish, pale;" Greek pelios "livid, dark;" polios "gray" (of hair, wolves, waves); Latin pallere "to be pale," pallidus "pale, pallid, wan, colorless;" Old Church Slavonic plavu, Lithuanian palvas "sallow;" Welsh llwyd "gray;" Old English fealo, fealu "dull-colored, yellow, brown." It also forms the root of words for "pigeon" in Greek (peleia), Latin (palumbes), and Old Prussian (poalis).

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

It forms all or part of: aneuploidy; decuple; fold (v.); -fold; furbelow; haplo-; hundredfold; manifold; multiple; octuple; polyploidy; -plus; quadruple; quintuple; sextuple; triple.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit putah "fold, pocket;" Albanian pale "fold;" Middle Irish alt "a joint;" Lithuanian pelti "to plait;" Old English faldan "to fold, wrap up, furl."

Proto-Indo-European root meaning "skin, hide."

It forms all or part of: erysipelas; fell (n.2) "skin or hide of an animal;" film; pell; pellagra; pellicle; pelt (n.) "skin of a fur-bearing animal;" pillion; surplice.

It is the hypothetical source of/evidence for its existence is provided by: Greek pella, Latin pellis "skin;" Old English filmen "membrane, thin skin, foreskin."

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

It forms all or part of: bibliopole; monopolize; monopoly; oligopolistic; oligopoly.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit panate "barters, purchases;" Lithuanian pelnas "gain;" Greek pōlein "to sell;" Old Church Slavonic splenu, Russian polon "prey, booty;" Old Norse falr, Dutch veil, German feil "for sale, venal."  

Proto-Indo-European root meaning "to thrust, strike, drive."

It forms all or part of: anvil; appeal; catapult; compel; dispel; expel; felt (n.) "unwoven fabric matted together by rolling or beating;" filter; filtrate; impel; impulse; interpellation; interpolate; peal; pelt (v.) "to strike (with something);" polish; propel; pulsate; pulsation; pulse (n.1) "a throb, a beat;" push; rappel; repeal; repel; repousse.

It is the hypothetical source of/evidence for its existence is provided by: Greek pallein "to wield, brandish, swing," pelemizein "to shake, cause to tremble;" Latin pellere "to push, drive;" Old Church Slavonic plŭstĭ.