Insert
late 15th century (in the sense ‘include (text) in a piece of writing’): from Latin insert- ‘put in’, from the verb inserere, from in- ‘into’ + serere ‘to join’.
wiktionary
From Latin insertus, past participle of inserō.
etymonline
insert (v.)
"to set in, put or place in," 1520s, from Latin insertus, past participle of inserere "to graft, implant," from in- "in" (from PIE root *en "in") + serere "join together, arrange, put in a row," from PIE root *ser- (2) "to line up." Middle English had inseren "to set in place, to graft, to introduce (into the mind)" (late 14c.), directly from the Latin verb. Related: Inserted; inserting.
insert (n.)
"something inserted," 1893, especially a paper, etc., placed in among the pages of a newspaper, magazine, etc., from insert (v.).