The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
pel-2
DEFINITION:
Flat; to spread. Oldest form *pel2-; variant *ple2-, colored to *pla2-, contracted to *pl-. Derivatives include field, planet, plasma, plastic, and polka. 1. Suffixed form *pel()-tu-.field, from Old English feld, open field, from Germanic *felthuz, flat land. 2. Suffixed form *pel()-t-es- (by-form of *pel()-tu-). a.feldspar, from Old High German feld, field; b.veldt, from Middle Dutch veld,velt, field. Both a and b from Germanic *feltha-, flat land. 3. Variant form *pl-.a. Suffixed form *pl-ru-.floor, from Old English flr, floor, from Germanic *flruz, floor; b. suffixed form *pl-no-.llano, piano2, plain, planarian, plane1, plane2, plane3, planish, plano-, planula; esplanade, explain, pianoforte, from Latin plnus, flat, level, even, plain, clear. 4. Suffixed zero-grade form *p-m-.palm1, palm2, palmary, from Latin palma (< *palama), palm of the hand. 5. Possibly extended variant form *plan-.a.planet; aplanatic, from Greek plansthai, to wander (< “to spread out”); b. perhaps Germanic *flan-.flâneur, from French flâner, to walk the streets idly, from a source akin to Old Norse flana, to wander aimlessly. 6. Suffixed zero-grade form *pl-dh-.–plasia, plasma, –plast, plaster, plastic, plastid, –plasty; dysplasia, metaplasm, toxoplasma, from Greek plassein (< *plath-yein), to mold, “spread out.” 7. O-grade form *pol-.a.polynya, from Russian poly, open; b.Polack, polka, from Slavic polje, broad flat land, field. (Pokorny pel- 805.) See also extensions plk-1 and plat-.
-2
-. 
r, floor, from Germanic *fl
, open; b. Polack, polka, from Slavic polje, broad flat land, field. (Pokorny pel
