INTERPENETRATE

interpenetrate, permeate

(verb) penetrate mutually or be interlocked; “The territories of two married people interpenetrate a lot”

permeate, pervade, penetrate, interpenetrate, diffuse, imbue, riddle

(verb) spread or diffuse through; “An atmosphere of distrust has permeated this administration”; “music penetrated the entire building”; “His campaign was riddled with accusations and personal attacks”

Source: WordNet® 3.1

Etymology

Verb

interpenetrate (third-person singular simple present interpenetrates, present participle interpenetrating, simple past and past participle interpenetrated)

To penetrate mutually or reciprocally.

To permeate or pervade.

Source: Wiktionary

In`ter*pen"e*trate, v. t.

Definition: To penetrate between or within; to penetrate mutually. It interpenetrates my granite mass. Shelley.

In`ter*pen"e*trate, v. i.

Definition: To penetrate each the other; to penetrate between bodies or their parts. Interpenetrating molding (Arch.), in late Gothic architecture, a decoration by means of moldings which seem to pass through solid uprights, transoms, or other members; often, two sets of architectural members penetrating one another, in appearance, as if both had been plastic when they were put together.

Source: Webster’s Unabridged Dictionary 1913 Edition