plāk- / Indo-European roots
Examples of words with the root plāk-: -plegia, apoplexy, archipelago, cataplexy, complacent, complain, flag, flake, flaw, fling, floe, fluke, leukoplakia, paraplegia, pelagic, placable, placate, placebo, placenta, placid, placoderm, placoid, plagal, plagiary, plagio-, plague, plaint, planchet, plangent, plank.
To be flat.Earliest form *pleh2k-, colored to *plah2k-, becoming *plāk-. Extension of pelə-2
▲ Derivatives include fluke1, flaw1, plead, placenta, archipelago.
1. floe from Old Norse flō, layer, coating, from Germanic *flōhō.
2. Variant form *plāg-.
a. fluke1 from Old English flōc, flatfish, from Germanic *flōk-;
b. flake1 from Middle English flake, flake, from a Scandinavian source probably akin to Norwegian flak, flat piece, flake, from Germanic *flakaz;
c. flake2 from Old Norse flaki, fleki, hurdle, from Germanic *flak-.
3. Extended form *plakā-. flag4, flaw1 from Old Norse flaga, layer of stone, from Germanic *flagō.
4. Possibly suffixed (stative) form *plak-ē-, to be calm (as of the flat sea) placebo, placid, plea, plead, pleasant, please; complacent from Latin placēre, to please, be agreeable.
5. Root noun *plak-. supplicate, supple from Latin supplex, suppliant (whence denominative supplicāre, to beg humbly, first attested in Archaic Latin as sub vos placō, I entreat you; sub, under; see upo)
6. Lengthened suffixed form *plāk-ā-. placable, placate from Latin plācāre, to calm (causative of placēre).
7. Nasalized form *pla-n-k-. planchet, plank from Latin plancus, flat, flat-footed.
8. Variant form *plag-.
a. Perhaps Latin plaga, net (? < "something extended") plagiary;
b. plagal, plagio-, playa from Greek plagos, side.
9. Root form *plak-. placenta, placoid; leukoplakia, placoderm from Greek plax, flat, flat land, surface, plate.
10. Possible variant form *pelag-. pelagic; archipelago from Greek pelagos, sea.
[Pokorny 1. plā-k- 831.]
To strike.Oldest form *pleh2k-, colored to *plah2k-, becoming *plāk-.
1. Nasalized variant forms *pla-n-k-, *pla-n-g-.
a. fling from Middle English flingen, to fling, from a Scandinavian source akin to Old Norse flengja, to flog, whip, from Germanic *flang-;
b. plaint, plangent; complain from Latin plangere, to strike (one's own breast), lament;
c. suffixed form *plang-yo-. plankton from Greek plazein, to drive away, turn aside.
2. Variant form *plāg-. plague from Latin plāga, a blow, stroke.
3. Suffixed form *plāk-yo-. plectrum, -plegia, plexor; apoplexy, cataplexy, paraplegia from Greek plēssein, to beat, strike.
[Pokorny 2. plāk- 832.]