suspicion (n.) Look up suspicion at Dictionary.com
c.1300, "act of suspecting; unverified conjecture of wrongdoing; mistrust, distrust," from Anglo-French suspecioun, corresponding to Old French suspicion, sospeçon "mistrust, suspicion" (Modern French soupçon), from Late Latin suspectionem (nominative suspectio) "mistrust, suspicion, fear, awe," noun of state from past participle stem of Latin suspicere "look up at" (see suspect (adj.)). Spelling in English influenced 14c. by learned Old French forms closer to Latin suspicionem. Used as a verb meaning "to suspect," it figures in literary representations of U.S. Western (Kentucky) slang from 1830s.

"Suspicion" words in other Indo-European languages also tend to be words for "think" or "look" with prefixes meaning "under, behind;" such as Greek hypopsia (hypo "under," opsis "sight"), hyponoia (noein "to think"); Lettish aizduomas (aiz "behind," duomat "think"); Russian podozrenie (Slavic podu "under," Old Church Slavonic zireti "see, look"); Dutch achterdocht (achter "behind," denken "to think").