From The Collaborative International Dictionary of English v.0.48 [gcide]:
Terrify \Ter"ri*fy\, v. t. [imp. & p. p. Terrified; p. pr. &
vb. n. Terrifying.] [L. terrere to frighten + -fy: cf. F.
terrifier, L. terrificare. See Terrific, and -fy.]
1. To make terrible. [Obs.]
[1913 Webster]
If the law, instead of aggravating and terrifying
sin, shall give out license, it foils itself.
--Milton.
[1913 Webster]
2. To alarm or shock with fear; to frighten.
[1913 Webster]
When ye shall hear of wars . . . be not terrified.
--Luke xxi. 9.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
terrify
v 1: fill with terror; frighten greatly [syn: terrify,
terrorize, terrorise]