Lewis Short
(verb) : per-sīdo, sēdi, sessum, 3
* To sink or settle down, to penetrate anywhere (poet.): pestilitas fruges persidit in ipsas,Lucr. 6, 1126; 1, 307: ubi frigidus imber Altius ad vivum persedit,Verg. G. 3, 442.
Charlton T. Lewis, Charles Short, A Latin Dictionary