In a manner characterized by remorse, regret, or a guilty conscience.
From 'compunctious' + adverbial suffix '-ly'. This creates the adverbial form allowing modification of verbs and actions.
While 'compunctiously' is grammatically valid, it's strikingly rare in modern English—perhaps because we now prefer shorter words like 'reluctantly' or 'guiltily,' showing how language efficiency gradually eliminates longer synonyms.
Complete word intelligence in one call. Free tier — 50 lookups/day.