Lewis Short
(adjective) : suf-frīgĭdus (subf-), a, um
* Rather cold or frigid (post-class. and very rare); trop.: argumentum,Amm. 17, 11, 4. —Adv.: suffrīgĭdē, rather coldly or frigidly: nimis minute ac prope etiam suffrigide,Gell. 2, 9, 4.
Charlton T. Lewis, Charles Short, A Latin Dictionary