In the wonderful world of TV, an interstitial is something that shows during commercial breaks that isn’t a commercial or something required, like a station ID an Emergency Broadcast System Test (not that we have those to worry about anymore, thank goodness). It might be a brief announcement of what network you’re watching, like this:
Or a brief news update:
Or the community bulletin board:
The ABC television network in the US used to have an interstitial that ran during the afternoon called "FYI," hosted by Hal Linden, star of that network’s Barney Miller.
Little shows like these are pretty common on kids’ TV. The Dutch, for example, had an animated character named Loeki de Leeuw (Loeki the Lion) who showed up during short breaks in TV shows. I think they tried him here in the US, and it didn’t go over very well.
CBS had short news stories that they fit in during the Saturday morning cartoons in the ’70’s and ’80’s. This is a news report about ice skating champion Diane de Leeuw, no relation to Loeki.
The Kaiser Broadcasting stations (of which WFLD in Chicago was one) had a number of little shows called "Snipets."
There are plenty more examples, and maybe you have some examples of your own, so feel free to include those in the comments.
The Sound of One Hand Typing 
I have never even heard of this word before but I know what you mean…we had “Good News” which was a 2 minute report on something that was good to hear. We also had these Schoolhouse Rock pieces that taught us about grammar etc… I hated them when I was a kid but I can still sing that first bit “Conjunction, Junction what’s your Function…”
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First thing that popped in my head was the medical term. But i kind of see the relationship.
Glad you gave us a vocab lesson
Turned Back
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Personally, I was surprised that it was used in medicine. But that’s just me.
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Interstitial. You’ve broadened my vocabulary. I hope, when bug season rolls around, I remember the itch relief home remedy Hal Linden was talking about. Alana ramblinwitham
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Learned something new today with a different meaning for interstitial. I knew it as a medical term from my years of doing medical terminology. Very interesting!
betty
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You can see how the word can apply in either case.
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Interesting. I didn’t know this usage. I immediately thought of the medical term.
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Like with ribcage stuff?
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It’s like fibrous tissue. Can be anywhere, lungs, kidneys. Interstitial: Pertaining to being between things, especially between things that are normally closely spaced. The word interstitial is much used in medicine and has specific meaning, depending on the context. For instance, interstitial cystitis is a specific type of inflammation of the bladder wall. Interstitial radiation involves placing radioactive material directly into a tumor. Interstitial pneumonia is inflammation of the lung that involves the mesh of lung tissue (alveolar septa) rather than the air spaces (alveoli). I type about it sometimes in my reports.
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This is a word I’ve seen but have never used in my life and it’s unlikely that I ever will. In the past I might have heard what this word meant and now that you’ve reminded me in depth maybe I’ll remember. Maybe not.
Arlee Bird
Tossing It Out
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It’s a fun one to pull out on occasion…
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I love Hal! I have to wonder if that home remedy really works. But alas I have nothing itchy to try it on. 😂
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I don’t have any milk…
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