trep·i·da·tion 
(trĕp′ĭ-dāshən)
(trĕp′ĭ-dāshən)n.
1. A state of alarm or dread; apprehension. See Synonyms at fear.
2. Archaic An involuntary trembling or quivering.
[Latin trepidātiō, trepidātiōn-, from trepidātus, past participle of trepidāre, to be in a state of confusion, from trepidus, anxious.]
trep′i·datious (-shəs) adj.