Lewis Short
(adjective) : intercălārĭus, a, um, intercalaris
* Of or for insertion, intercalary: mensis,an intercalary month,Liv. 1, 19, 6; 37, 59, 2; Suet. Caes. 40; the same absol.: intercalarius,Cic. Verr. 2, 2, 52, § 130: annus,leap-year,Plin. 2, 47, 48, § 130; 18, 25, 57, § 207.
Charlton T. Lewis, Charles Short, A Latin Dictionary