To ingratiate; to obtain access to or introduce something by subtle, cunning or artful means.
To hint; to suggest tacitly (usually something bad) while avoiding a direct statement.
To creep, wind, or flow into; to enter gently, slowly, or imperceptibly, as into crevices.
To insert anything somewhere (especially between other things), such as an affix into a word. (Compare interpolate.)
To insert an extra month into a calendar for the same purpose. The Hebrew calendar has such a month.
To insert a substance between two or more molecules, bases, cells, or tissues.
To insert an extra leap day into a calendar in order to maintain synchrony with natural phenomena.