Lewis Short
(verb) : circum-sīdo, ĕre
* To set or place one's self around in a hostile manner, to besiege (several times in Livy; elsewhere rare): Plistiam,Liv. 9, 21, 6; 36, 13, 7; 41, 19, 10; 42, 56, 5: regem urbemque Philippopolim,Tac. A. 3, 38.
Charlton T. Lewis, Charles Short, A Latin Dictionary