Lewis Short
(verb) : sŭb-intro, āvi, ātum, 1
* To go into secretly, to enter by stealth, steal into (late Lat.); trop.: populo bellicoso ludorum scenicorum subintravit insania, Aug. Civ. Dei, 1, 32; so Tert. adv. Marc. 5, 3 al.
Charlton T. Lewis, Charles Short, A Latin Dictionary