English
interpenetration
From inter- + penetration.
A compound of inter- + penetration
Proto-Indo-European *h₁én ‘in’
Proto-Indo-European *h₁entér ‘between’
Proto-Italic *n̥ter ‘between’
Latin inter ‘between’
English inter-
Proto-Indo-European *peh₂- ‘to protect, to ward’
Latin penetrō ‘to penetrate’
Latin penetrātiō ‘piercing, penetration’
Old French penetracïon
Middle English penetracioun
English penetration
Today it means
noun The act of penetrating between or within other substances; mutual penetration.
Language periods are conventional ranges, not dates for this word.
Etymograph / interpenetration