credulous

The word 'credulous' is built directly on the Latin verb 'credere', meaning 'to believe' or 'to trust'. The suffix '-ulous' is a productive adjectival ending in English, derived from Latin '-ulosus', which indicates a strong propensity or tendency. Thus, the literal construction means "full of belief" or "prone to believing." Over time, this inherent tendency acquired a negative connotation, shifting from a neutral state of being trusting to the modern sense of being overly or naively trusting, and therefore easily misled. This semantic shift reflects a cultural valuation where excessive belief without evidence is seen as a weakness.

Structure: cred (believe) + ulous (full of, tending to) - cred: From Latin 'credere' (to believe, trust). A root conveying belief or trust. - ulous: A Latin adjectival suffix, a variant of '-ulous', meaning 'full of', 'prone to', or 'tending to'.