Infantilizer

Part of speech: noun

Definitions

1. A person or entity that promotes childish behavior or attitudes in others while undermining their maturity
2. An individual or thing that encourages the perception of adults as naive or juvenile, hindering their growth
3. A person who makes others seem or behave less mature than they are

Etymology: "Infantilizer" is simply "infantilize" with the agent suffix "-er" added, so it names someone who infantilizes others. The base verb "infantilize" comes from "infantile," which descends from Latin "infans," meaning "unable to speak" or "young child," built from "in-" (not) and "fans," the present participle of "fari," to speak. The suffix "-ize" turns the adjective into a verb meaning to treat someone as a child, and "-er" adds the sense of the one doing it.