This is the superlative adverb meaning 'most quickly' or 'as quickly as possible.' In Acts 17:15, those escorting Paul give instructions that Silas and Timothy should come to him 'as quickly as possible.' The term emphasizes urgency and maximal haste. Classical usage described the swiftest runners or the fastest ships. The cross-linguistic evidence shows varied expressions of urgency: Spanish 'pronto' (soon), French 'le plus vite' (the fastest), German preserving the Greek form. All convey pressing need for speed.