English
amplituhedron
From amplitude + -hedron.
Formed from amplitude + -hedron
The story
Coined by Nima Arkani-Hamed and Jaroslav Trnka in 2013 and published in 2014 in an article in the Journal of High Energy Physics.
Today it means
noun A mathematical structure which encodes the integrand of an amplitude in planar N=4 super Yang-Mills theory, used in calculations of scattering amplitudes of particle interactions.
Language periods are conventional ranges, not dates for this word.
Etymograph / amplituhedron