quickly; as soon as possible; without delay
Adverbial phrase emphasizing promptness; often used in requests or suggestions to do something early or right away.
Please reply as soon as possible.
You'd better start right away.
Alternate spelling using 事 for こと; less common but acceptable.
Phrase composed of the adjective 早い (early, fast) and the nominalizer こと, literally 'early thing', used adverbially to mean 'quickly'.