The Proto-Indo-European word *sph₁rós
Word *sph₁rós
Meaning fat, rich
See also Proto-Indo-European: *speh₁- ‘to be satisfied, to be filled, to thrive’
Synonyms *dʰeb-, pen-, *tegus, *m(e)hₐd-, *sélpes-

Comments
Mallory J.P. and Adams D. (2006)