không đáng tin cậy 
untrustworthy, unreliable [ không ] : (1) no, not; (question tag); (2) air; (3) empty
[ đáng ] : to deserve, to merit; worthy, worth
[ tin ] : news, report; to believe, trust
[ cậy ] : persimmon
Most Common Compounds Set 1:
Most Common Compounds Set 2 :