The Collaborative International Dictionary of English v.0.48:

Guarded \Guard"ed\, a.
   Cautious; wary; circumspect; as, he was guarded in his
   expressions; framed or uttered with caution; as, his
   expressions were guarded. -- Guard"edly, adv. --
   Guard"ed*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

guardedly
    adv 1: in a conservative manner; "we estimated the number of
           demonstrators conservatively at 200,000." [syn:
           conservatively, cautiously, guardedly]