An Etymological Dictionary of the German Language/eigen
eigen, adj., ‘own, pertinent, peculiar, odd,’ from the equiv. ModHG. eigen, OHG. eigan; an adj. common to Teut.; comp. OSax. êgan, Du. eigen, AS. âgen, E. own, OIc. eiginn; Goth. used swês for *aigans. The old adj. eigen is, as the suffix n shows, Prop. a partic. ending in -ana- of a vb., which only appears, however, as a pret. pres., meaning ‘to possess,’ throughout the Teut. group; comp. Goth. áigan, (áihan), OIc. eiga, AS. âgan, ‘to have’ (E. to owe), pret. in AS. âhte, in E. ought, whence also AS. âgnian, E. to own. The Teut. root aig (aih), from pre-Teut. aik, preserved in these words, has been connected with the Sans. root îç, ‘to possess, have as one's own,’ the partic. of which, îçâná-s (îçâna-s), agrees exactly with HG. eigan, Goth. *aigans. In ModHG. Fracht (which see) we have a subst. formed with a dental suffix (Goth. aihts, ‘property, possession,’ OHG. êht).