I. adjective
Synonyms: doubtful 1, doubtable, dubious, open, problematic, shaky, suspicious, uncertain, unclear, unsure
Idioms: ||a bit thin ( or thick), open to suspicion
II. verb
1.
Synonyms: distrust , doubt, misdoubt, mistrust, ||suspicion
Idioms: have doubts about
2.
Synonyms: understand 3, assume, believe, conceive, expect, gather, imagine, ||reckon, suppose, think
Idioms: be inclined to think