Definition of electronic check (e-check): An electronic payment process that resembles the function of paper checks, but offers greater security and more features. An eCheck (or electronic check) is an electronic version of a paper check used to Anyone with a checking account can pay by eCheck through CitePayUSA. Funding a Xoom money transfer with an eCheck is easy and secure. All you need is a U.S. bank account. An eCheck is an electronic payment where the money.