In a manner showing self-restraint and unwillingness to indulge in something; with moderation and temperance.
From 'abstinent' plus the adverbial suffix '-ly'; this adverb form developed to describe actions performed with restraint and discipline.
Medieval manuscripts describe monks who lived 'abstinently,' eating only bread and water—the word choice itself suggested moral superiority, as if choosing plain language elevated the description of their austere lives.
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