What does -wide add?
-wide comes from the adjective "wide" (broad, extensive). Attached to a place or group noun it creates a modifier meaning "covering or extending throughout that entire scope": • nation + wide = nationwide = covering the whole nation • world + wide = worldwide = covering the whole world • city + wide = citywide = covering the whole city • industry + wide = industry-wide = affecting the whole industry The result works as an adjective ("a nationwide survey") or an adverb ("the campaign spread nationwide").