interstitial

adjective

in·​ter·​sti·​tial ˌin-tər-ˈsti-shəl 

1

: occurring in or being an interval or intervening space or segment : of, relating to, or forming an interstice

an interstitial space

… the site has been running interstitial ads, which consist of a full page of advertising between editorial pages, for a little more than a year.

—Carl Sullivan

2

a

: situated within but not restricted to or characteristic of a particular organ or tissue

—used especially of fibrous tissue

b

: affecting the interstitial tissues of an organ or part

interstitial cystitis

3

: being or relating to a crystalline compound in which usually small atoms or ions of a nonmetal occupy holes between the larger metal atoms or ions in the crystal lattice

interstitially

ˌin-tər-ˈsti-shə-lē 

adverb

Examples of interstitial in a Sentence

Recent Examples on the Web

The symptoms often include muscle pain, arthritis, rashes, and rapidly progressing interstitial lung disease (RP-ILD), which is severe lung scarring. —Jennifer Chesak, Verywell Health, 21 May 2024

There will be live performances to honor six of this year’s honorees at Tuesday’s event, and interstitial video presentations for the other four. —Paul Grein, Billboard, 20 May 2024

Word History

First Known Use

1646, in the meaning defined at sense 1

Kids Definition

interstitial

adjective

in·​ter·​sti·​tial ˌint-ər-ˈstish-əl 

: relating to or located in the interstices

interstitially

-ˈstish-ə-lē 

adverb

Medical Definition

interstitial

adjective

in·​ter·​sti·​tial ˌint-ər-ˈstish-əl 

1

: situated within but not restricted to or characteristic of a particular organ or tissue

—used especially of fibrous tissue

2

: affecting the interstitial tissues of an organ or part

interstitial hepatitis

3

: occurring in the part of a fallopian tube in the wall of the uterus

interstitial pregnancy

interstitially

-ə-lē 

adverb