Platonic

Concise Oxford English Dictionary © 2008 Oxford University Press:
Platonic /pləˈtɒnɪk/

▶adjective

• 1 of or associated with the Greek philosopher Plato or his ideas.

• 2 (platonic) (of love or friendship) intimate and affectionate but not sexual.

– derivatives
platonically adverb.

– origin C16: via L. from Gk Platōnikos, from Platōn ‘Plato’.