Definition of "frightful"

(obsolete) Full of fright, whether

1. Afraid, frightened.  quotations  examples

   Quotations

   • Ðis frigtful ðus a-biden,Quiles ðis daiȝes for ben gliden.

     c. 1250, Genesis and Exodus, line 3459

2. Timid, fearful, easily frightened.  quotations  examples

   Quotations

   • See how the frightful herds run from the wood.

     1613, William Browne, Britannia's Pastorals

Full of something causing fright, whether

1. Genuinely horrific, awful, or alarming.  examples

2. (hyperbolic) Unpleasant, dreadful, awful (also used as an intensifier).  quotations  examples

   Quotations

   • Francis Urquhart: What a frightful little man. Where do they find them these days?Tim Stamper: God knows. If I had a dog like that, I'd shoot it.Francis Urquhart: Well, yes. Quite.

     1990, House of Cards, season 1, episode 1

(dialect) Frightfully; very.  quotations  examples