Source : Webster's Revised Unabridged Dictionary (1913)

Timorous \Tim"or*ous\, a. [LL. timorosus, from L. timor fear;
   akin to timere to fear. See {Timid}.]
   1. Fearful of danger; timid; deficient in courage. --Shak.

   2. Indicating, or caused by, fear; as, timorous doubts. ``The
      timorous apostasy of chuchmen.'' --Milman. --
      {Tim"or*ous*ly}, adv. -- {Tim"or*ous*ness}, n.

Source : WordNet®

timorously
     adv : in a timorous and trepid manner [syn: {trepidly}]