1) Apprehensive 2) Cautious 3) Chary 4) Circumspect 5) Disbelieving 6) Distrustful 7) Distrustful, slang 8) Doubtful 9) Dubious 10) Exclusively Saxon word 11) Exclusively Anglo word 12) Far from convinced 13) Far from trusting 14) Fearful 15) Feeling suspicious 16) Guarded 17) Guardedly suspicious 18) Gun-shy 1) Distrustful 2) Doubtful 3) Mistrustful 4) Suspicious 5) Untrusting 6) Wary 
Leery is slang for wary, suspicious, shy, cautious.
[adj] - openly distrustful and unwilling to confide
mistrustful adjective openly distrustful and unwilling to confide
[SAT terms] openly distrustful and unwilling to confide openly distrustful and unwilling to confide