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 interstitial musical numbers don’t add much, but rollicking readings have the audience in stitches — and Nordland’s real-time reactions are a treat, too. —Jared Kaufman, Twin Cities, 6 Aug. 2025

And even with the interstitial videos going away at that point, the role of live photography is just as key as the show goes on. —Chris Willman, Variety, 8 June 2025

Amid the mini-thon, there will be interstitial videos featuring Baccarin and Fire Country front man/co-creator Max Thieriot. —Matt Webb Mitovich, TVLine, 10 July 2025

Realize or continue to check that there's no such thing as an interstitial moment because either everything is sacred or nothing is sacred. —Outside Online, 25 June 2025

Word History

First Known Use

1646, in the meaning defined at sense 1

Rhymes for interstitial

• artificial
• beneficial
• cicatricial
• nonjudicial
• nonofficial
• prejudicial
• sacrificial
• superficial
• unofficial
• extrajudicial
• semiofficial
• initial

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