The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
dheigh-
DEFINITION:
To form, build. Oldest form *dheih-, becoming *dheigh- in centum languages. Derivatives include dairy, lady, dough, and paradise. 1.dairy, from Old English dge, bread kneader, from Germanic *daigjn-.2.lady, from Old English compound hlfdige, mistress of a household (< “bread kneader”; hlf, bread, loaf), from Germanic *dg-.3. Suffixed o-grade form *dhoigh-o-.a.dough, from Old English dg, dough; b.teiglach, from Old High German teic, dough. Both a and b from Germanic *daigaz.4. Suffixed zero-grade form *dhigh-r-.figure, figurine; configure, disfigure, prefigure, transfigure, from Latin figra, form, shape (< “result of kneading”). 5. Nasalized zero-grade form *dhi-n-gh-.fainéant, faint, feign, feint, fictile, fiction, figment; effigy, from Latin fingere, to shape. 6. Probable nasalized zero-grade form *dhi-n-g(h)-.thigmotaxis, thixotropy, from Greek thinganein, to touch. 7. Suffixed o-grade form *dhoigh-o-.paradise, from Avestan daza-, wall (originally made of clay or mud bricks). (Pokorny dheih- 244.)
h-, becoming *dheigh- in centum languages. 
ge, bread kneader, from Germanic *daigj
n-. 2. lady, from Old English compound hl
f, bread, loaf), from Germanic *d
g-. 3. Suffixed o-grade form *dhoigh-o-. a. dough, from Old English d
r
za-, wall (originally made of clay or mud bricks). (Pokorny dhei
