The General Mixed-Use (GMU) district is established to provide a wide variety of professional offices and institutions and a broad range of light and moderate intensity commercial uses proximate to residential and more intense business districts
Read it in the chapter →How this ordinance defines it
The operative definition is the local one. Codes routinely subdivide a category into tiers — “day care 2, family”, “group home 2” — and attach different permissions to each, so only Portsmouth’s own text settles what this covers.