EXAMPLES FROM THE WEB FOR INTERCALATE
To prevent this it was customary at regular intervals to intercalate days or months.
The present appears the fittest place in which to intercalate remarks concerning them.
So far it would suffice, in accounting for the facts, to intercalate between A and B a few terms, which would remain discrete.
The rule was to intercalate a day in every fourth year (quarto quoque anno).