In a manner befitting a citizen; showing the qualities, behavior, or attitude expected of a responsible citizen.
From 'citizen' plus '-ly' (Old English -lic, meaning 'like' or 'of the nature of'); the '-ly' suffix creates adjectives describing manner or character.
This quiet adjectival form encodes an entire civic philosophy—the idea that there's a 'right way' to be a citizen, a comportment and set of virtues that characterize good membership in society.
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