INTERCALATE
intercalate
(verb) insert (days) in a calendar
Source: WordNet® 3.1
Etymology
Verb
intercalate (third-person singular simple present intercalates, present participle intercalating, simple past and past participle intercalated)
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.
(molecular biology) To insert a substance between two or more molecules, bases, cells, or tissues.
To insert anything somewhere (especially between other things), such as an affix into a word. (Compare interpolate.)
Source: Wiktionary
In*ter"ca*late, v. t. [imp. & p. p. Intercalated; p. pr. & vb. n.
Intercalating.] Etym: [L. intercalatus, p. p. of intercalare to
intercalate to intercalate; inter between + calare to call, proclaim.
See Calendar.]
1. (Chron.)
Definition: To insert, as a day or other portion of time, in a calendar.
2. To insert among others, as a verse in a stanza; specif. (Geol.),
to introduce as a bed or stratum, between the layers of a regular
series of rocks.
Beds of fresh-water shells . . . are intercalated and interstratified
with the shale. Mantell.
Source: Webster’s Unabridged Dictionary 1913 Edition