Lewis Short
ex-pallesco, lŭi, 3
* V. inch. n., to grow or turn very pale (perh. occurring only in the perf.): viden' ut expalluit!Plaut. Curc. 2, 3, 32; Ov. M. 6, 602; Plin. Ep. 1, 5, 13; Luc. 1, 539 al.: erubuisse, expalluisse, titubasse ... signa conscientiae sunt,Auct. Her. 2, 5, 8.—Poet., act., with acc.: Pindarici fontis qui non expalluit haustus,who feared not to drink,Hor. Ep. 1, 3, 10; Sil. 12, 146.
Charlton T. Lewis, Charles Short, A Latin Dictionary