what is it called when you sell the rights to a tv show nationwide?

It’s usually called TV syndication or a licensing/distribution deal. If you mean selling the rights for a show to air across the country, “national syndication” is the most common term, and the deal itself is often a license agreement or distribution agreement.

Common terms

• Syndication : selling a show to multiple stations or outlets for broadcast in different markets.

• Licensing : granting permission to air the show under agreed terms.

• Distribution rights : the broader rights package that lets a distributor place the show with broadcasters or platforms.

Plain-English version

If a producer sells a TV show nationwide, they’re usually not “selling” it outright in everyday terms. More often, they’re licensing the rights to a network, distributor, or stations so the show can be shown in that territory.

Example

A sitcom can start on one local station and later be sold to stations across the country for reruns. That later stage is typically called syndication.

TL;DR

The short answer is: syndication for nationwide TV exposure, and licensing/distribution rights for the legal deal behind it.