The term 'Man on a 'HOG'' is a slang phrase used to refer to a BIKER, or someone who rides a motorcycle. The crossword solution for this term is 'BIKER, ' which is a five-letter word. A BIKER is someone who rides a motorcycle, often as a hobby or lifestyle choice. Bikers often form clubs and ride together in groups, and the term 'Man on a 'HOG'' is a reference to the Harley-Davidson motorcycles that are popular among bikers.