Antonyms of adj suspicious

2 senses of suspicious

Sense 1
leery, mistrustful, suspicious, untrusting, wary -- (openly distrustful and unwilling to confide)

INDIRECT (VIA distrustful) -> trustful, trusting -- (inclined to believe or confide readily; full of trust; "great brown eye, true and trustful"- Nordhoff & Hall)

Sense 2
fishy, funny, shady, suspect, suspicious -- (not as expected; "there was something fishy about the accident"; "up to some funny business"; "some definitely queer goings-on"; "a shady deal"; "her motives were suspect"; "suspicious behavior")

INDIRECT (VIA questionable) -> unquestionable -- (incapable of being questioned; "unquestionable authority")

Similarity of adj suspicious

2 senses of suspicious

Sense 1
leery, mistrustful, suspicious, untrusting, wary -- (openly distrustful and unwilling to confide)
       => distrustful (vs. trustful) -- (having or showing distrust; "a man of distrustful nature"; "my experience...in other fields of law has made me distrustful of rules of thumb generally"- B.N.Cardozo; "vigilant and distrustful superintendence"- Thomas Jefferson)

Sense 2
fishy, funny, shady, suspect, suspicious -- (not as expected; "there was something fishy about the accident"; "up to some funny business"; "some definitely queer goings-on"; "a shady deal"; "her motives were suspect"; "suspicious behavior")
       => questionable (vs. unquestionable) -- (subject to question; "questionable motives"; "a questionable reputation"; "a fire of questionable origin")