To insert an extra leap day into a calendar in order to maintain synchrony with natural phenomena. / To insert an extra month into a calendar for the same purpose. The Hebrew calendar has such a month.

Third-person singular simple present indicative form of intercalate

simple past tense and past participle of intercalate

(geology) interleaved, formed in distinctly alternating layers.

plural of intercalation

A period inserted into a calendar as in a leap year. / (chemistry) The reversible insertion of a molecule between two others. / (geology) A layer introduced into a pre-existing sequence.

(chemistry) That intercalates

present participle of intercalate

plural of intercalator

That which intercalates / (biochemistry) Any of several classes of small molecule that insert themselves into the structure of DNA