Lewis Short
(verb) : spisso, āvi, ātum, 1, id..
* Lit., to thicken, make thick, condense (poet. and in post-Aug. prose; esp. freq. in Pliny the elder; cf. denso): omne lac igne spissatur,Plin. 11, 41, 96, § 238; so, spissatum lac,id. 20, 7, 24, § 58: farinae modo spissatur in panem,id. 13, 4, 9, § 47: ignis densum spissatus in aëra transit,Ov. M. 15, 250; cf. Luc. 4, 77: (aquilo) sanum corpus spissat,Cels. 2, 1 med.; cf. Plin. 26, 13, 83, § 134; Sen. Ep. 90, 10.—*
* Trop., to urge on, hasten an action, i. e. to perform it more rapidly: spissare officium,Petr. 140.
Charlton T. Lewis, Charles Short, A Latin Dictionary