dubious

the word 'dubious' entered english in the mid-16th century, directly from the latin adjective 'dubius', meaning 'wavering' or 'uncertain'. this latin term itself is derived from the root 'duo-', meaning 'two', reflecting the ancient concept of doubt as a state of being of two minds, caught between two possibilities. the suffix '-ous', of latin origin, was added to form an adjective meaning 'full of doubt'. thus, the literal construction 'full of two-mindedness' evolved into the modern abstract meanings describing something that causes hesitation, is untrustworthy, or is of uncertain authenticity.

Structure: dubi (doubt) + ous (adjective suffix) dubi (from latin 'dubius', meaning 'doubtful', 'wavering'); ous (a suffix forming adjectives, from latin '-osus', meaning 'full of', 'characterized by')