Dictionary.com
definitions

orexis

[aw-rek-sis, oh-rek-]
noun Psychology.
  1. the affective and conative character of mental activity as contrasted with its cognitive aspect; the appetitive aspect of an act.

Origin of orexis

1610–20; < Latin: longing, appetite < Greek órexis desire, equivalent to orég(ein) to desire + -sis -sis
Related formso·rec·tic [aw-rek-tik, oh-rek-] /ɔˈrɛk tɪk, oʊˈrɛk-/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018