English
intergradation
From intergrade + -ation.
A compound of intergrade + -ation
Proto-Indo-European *gʰredʰ-
Latin gradior ‘to step, walk, stride’
Latin intergredior ‘to intergrade’
English intergrade
Today it means
noun a gradual merging of two things
Language periods are conventional ranges, not dates for this word.
Etymograph / intergradation