I'm trying to remember the umbrella term for terms like "snail mail", "landline", and "terrestrial radio"; ie, terms that have been created in order to express their distinction from newer (and higher-tech) forms of the same thing.

So, whereas "radio" was once the standard term, we now have to use "terrestrial radio" to distinguish it from satellite radio.

thanks for your help

retronyms!

Welcome, srt.

that's it.

thanks!