wary

adj. cautious, suspicious

Adjective
1. marked by keen caution and watchful prudence; "they were wary in their movements"; "a wary glance at the black clouds"; "taught to be wary of strangers"
(antonym) unwary
(similar) on guard, on one's guard(p), upon one's guard(p), on your guard
(attribute) wariness, chariness
2. openly distrustful and unwilling to confide
(synonym) leery, mistrustful, suspicious, untrusting
(similar) distrustful

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

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

  awry

Synonyms and related words:
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