You searched for: “interspersal”
interspersal (s) (noun), interspersals (pl)
The act of combining one thing at intervals within other things: "The artist made an interspersal of illustrations in various parts of the contents of the text."
This entry is located in the following units: inter-, intero- (page 16) -sperse, -spersed, -spersing, -spersion; spars-; -spargic (page 1)