interstitial

American  

[in-ter-stish-uhl] / ˌɪn tərˈstɪʃ əl /

adjective

1. pertaining to, situated in, or forming interstices.

2. Anatomy. situated between the cells of a structure or part.

   interstitial tissue.

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noun

1. Crystallography. an imperfection in a crystal caused by the presence of an extra atom in an otherwise complete lattice.

interstitial British  

/ ˌɪntəˈstɪʃəl /

adjective

1. of or relating to an interstice or interstices

2. physics forming or occurring in an interstice

   an interstitial atom

3. chem containing interstitial atoms or ions

   an interstitial compound

4. anatomy zoology occurring in the spaces between organs, tissues, etc

   interstitial cells

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noun

1. chem an atom or ion situated in the interstices of a crystal lattice

Other Word Forms

• interstitially
  adverb

Etymology

Origin of interstitial

1640–50; < Latin interstiti ( um ) interstice + -al ¹

Explanation

Interstitial has to do with small spaces, called "interstices." Interstices can be literal spaces, like the gaps between your teeth, or they can be figurative, like the few minutes you have between classes. You'll notice that when the noun interstice becomes the adjective interstitial, the -ce- changes to a -ti-. That's a fairly common spelling shift — difference becomes differential, for instance, where the -ti- is actually pronounced like -sh- or -ch-.

Example Sentences

See Examples For:

interstitial

BPC-157 was discovered by researchers in Croatia in the 1990s and is primarily used as a treatment for interstitial cystitis, knee pain and ulcerative colitis.

From MarketWatch ● Jul. 23, 2026

Salmon is married to artist and illustrator Fiona Hawthorne, who previously revealed she was diagnosed with a rare lung condition, interstitial lung disease, which requires her to use an oxygen tank.

From BBC ● Jan. 1, 2026

Insmed also said on Wednesday that it was acquiring the antibody INS1148, and launching a Phase 2 development to study if that can treat interstitial lung disease and moderate-to-severe asthma.

From Barron's ● Dec. 18, 2025

There, it mixes with interstitial fluid to remove metabolic waste, including Aβ.

From Science Daily ● Nov. 11, 2025

Africa has parasites so particular and diverse as to occupy every niche of the body: intestines small and large, the skin, the bladder, the male and female reproductive tracts, interstitial fluids, even the cornea.

From "The Poisonwood Bible" by Barbara Kingsolver