fogey (n.)

also fogy, "an old, dull fellow," 1780, Scottish foggie, originally "army pensioner or veteran," perhaps connected to fogram (1772) "old-fashioned," also "old-fashioned person;" or from fog (n.2) in an obsolete senses of "moss," or from foggy "bloated, fat" (1520s), which perhaps is an extended sense of fog (n.2). Related: Fogeydom; fogeyish; fogeyism.