suspicious (adj.) Look up suspicious at Dictionary.com
"deserving of or exciting suspicion," mid-14c., from Old French suspecious, from Latin suspiciosus "exciting suspicion" (see suspicion). Meaning "full of or inclined to feel suspicion" is attested from c.1400. Edgar Allan Poe (c.1845) proposed suspectful to take one of the two conflicting senses. Related: suspiciously; suspiciousness.