Of or pertaining to interstices; intermediate; within the tissues; as, interstitial cavities or spaces in the tissues of animals or plants. [1913 Webster]

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OXFORD DICTIONARY

interstitial, adj. of, forming, or occupying interstices.

Derivative

interstitially adv.

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ROGET THESAURUS

interstitial

Interiority

N interiority, inside, interior, interspace, subsoil, substratum, intrados, contents, substance, pith, marrow, backbone, heart, bosom, breast, abdomen, vitals, viscera, entrails, bowels, belly, intestines, guts, chitterings, womb, lap, penetralia, recesses, innermost recesses, cave, interior, internal, inner, inside, inward, intraregarding, inmost, innermost, deep seated, gut, intestine, intestinal, inland, subcutaneous, abdominal, coeliac, endomorphic, interstitial, inwrought, inclosed, home, domestic, indoor, intramural, vernacular, endemic, internally, inwards, within, in, inly, here in, there in, where in, ab intra, withinside, in doors, within doors, at home, in the bosom of one's family.

Interposition

N interposition, interjacence, intercurrence, intervenience, interlocation, interdigitation, interjection, interpolation, interlineation, interspersion, intercalation, interpenetration, permeation, infiltration, intervention, interference, intrusion, obtrusion, insinuation, insertion, dovetailing, embolism, intermediary, intermedium, go between, bodkin, intruder, interloper, parenthesis, episode, flyleaf, partition, septum, diaphragm, midriff, dissepiment, party wall, panel, room divider, halfway house, interjacent, intercurrent, intervenient, intervening, intermediate, intermediary, intercalary, interstitial, embolismal, parenthetical, episodic, mediterranean, intrusive, embosomed, merged, between, betwixt, twixt, among, amongst, amid, amidst, mid, midst, in the thick of, betwixt and between, sandwich-wise, parenthetically, obiter dictum.

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