Kleinian

English

Etymology

Klein +‎ -ian

Adjective

Kleinian (comparative more Kleinian, superlative most Kleinian)

1. Of or pertaining to Christian Felix Klein (1849–1925), German mathematician.
   • 1986, S. Samuil Leibovich Krushkal', B. Boris Nikolaevich Apanasov, N. Nikolai Aleksandrovich Gusevskii, Kleinian Groups and Uniformization in Examples and Problems, page 166:

     Prove that if a Kleinian group G does not contain parabolic elements and is isomorphic to the fundamental group of a closed orientable surface, then G is either quasi-Fuchsian or degenerate […]

2. Of or pertaining to Melanie Reizes Klein (1882–1960), Austrian-born British psychoanalyst who devised novel therapeutic techniques for children.
   • 1989, Elizabeth Abel, Virginia Woolf and the Fictions of Psychoanalysis, page 11:

     The second three months of life, the critical era in the Kleinian narrative, are marked by a shift from the paranoid to the "depressive" position produced by the infant's growing ability to integrate contradictory perceptions.