fogy

The origin of "fogy" is obscure, with its first recorded use in the late 18th century. It is most likely a variant of the slightly earlier military slang term "fogey," which referred to a veteran soldier or an old, infirm pensioner. One plausible theory suggests a connection to the Scottish word "foggy," meaning moss-grown or flabby, metaphorically extended to imply someone mentally sluggish or stuck in the past. From these beginnings, the term evolved to its modern abstract meaning, denoting any person, not just a soldier, who holds obstinately to old-fashioned ways and ideas.

The word is a simplex. Its origin is uncertain, but it is likely a variant of the earlier term "fogey." The functional role is that of a complete, unanalyzable noun stem.