Wordnet 3.0
ADJECTIVE (1)
1. 
 timid by nature or revealing timidity; 
- Example: "timorous little mouse"- Example: "in a timorous tone"- Example: "cast fearful glances at the large dog"[syn: fearful, timorous, trepid]
The Collaborative International Dictionary of English v.0.48:
Trepid \Trep"id\, a. [L. trepidus.]
   Trembling; quaking. --Thackeray.
   [1913 Webster]
WordNet (r) 3.0 (2006):
trepid
    adj 1: timid by nature or revealing timidity; "timorous little
           mouse"; "in a timorous tone"; "cast fearful glances at
           the large dog" [syn: fearful, timorous, trepid]