11 letters · 13 points in Scrabble
verb insert (days) in a calendar
originThe verb is first attested in 1614, the noun in 1964; borrowed from Latin intercalātus, perfect passive participle of intercalō (“to proclaim that a day, an event, etc. has been intercalated; to insert”) (see -ate (verb-forming suffix) and -ate (noun-forming suffix)), from inter- (“between, among”) + calō (“to call; to proclaim”).
Etymology from Wiktionary, CC BY-SA 3.0