1. (a.) Cautious of danger; carefully watching and guarding against deception, artifices, and dangers; timorously or suspiciously prudent; circumspect; scrupulous; careful.

2. (a.) Characterized by caution; guarded; careful.

Argus-eyed Machiavellian Machiavellic Pyrrhonic Scotch acute agnostic all ears all eyes arch artful astute aux aguets cagey calculating canny careful cautious chary circumspect clever considerate crafty cunning custodial cute deceitful deep deep-laid designing diplomatic discreet disinclined to believe disposed to doubt distrustful doubtful doubting dubious eagle-eyed feline foxy from Missouri frugal gingerly guarded guileful hard of belief hawk-eyed impervious to persuasion in doubt inconvincible incredulous ingenious insidious inventive keen-eyed knowing leery lidless mistrustful mistrusting observant on guard on the lookout on the watch open-eyed pawky politic provident prudent questioning ready resourceful safe saving scheming scrupulous serpentine sharp sharp-eyed shifty shrewd shy shy of belief skeptical sleepless slick slippery sly smooth snaky sneaky sophistical stealthy strategic subtile subtle supple suspecting suspicious tactical thrifty trickish tricksy tricky uncertain unconvincible uncredulous unpersuadable unpersuasible untrusting unwasteful unwilling to accept vigilant vulpine watchful wily with open eyes