Meaning

noun a folded section placed between the leaves of another publication

noun an artifact that is inserted or is to be inserted

noun (broadcasting) a local announcement inserted into a network program

originFrom Latin insertus, past participle of inserō, from in- + serō (“join, bind together, connect, entwine, interweave”), ultimately from Proto-Indo-European *ser- (“to bind, put together, to line up”). Compare exsert.

Etymology from Wiktionary, CC BY-SA 3.0