1. [v]  place in a place where something cannot be removed or someone cannot escape; "The parents locked her daughter up for the weekend"; "She locked her jewels in the safe"
2. [v]  close with or as if with a tight seal; "This vacuum pack locks in the flavor!"

Lock-In
In honor of the eighth-graders' graduation, Willie's church is holding a Lock-In, including an exciting contest that might also introduce some of the participants to Jesus.

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When an existing standard becomes almost impossible to supersede because of the cost or logistical difficulties involved in convincing all its users to switch something different and, typically, incompatible.

The common implication is that the existing standard is notably inferior to other comparable standards developed before or since.

Things which have been accused of benefiting from lock-in in the absence of being truly worthwhile include: the QWERTY keyboard; any well-known operating system or programming language you don't like (e.g., see "Unix conspiracy"); every product ever made by Microsoft Corporation; and most currently deployed formats for transmitting or storing data of any kind (especially the Internet Protocol, 7-bit (or even 8-bit) character sets, analog video or audio broadcast formats and nearly any file format).

Because of network effects outside of just computer networks, Real World examples of lock-in include the current spelling conventions for writing English (or French, Japanese, Hebrew, Arabic, etc.); the design of American money; the imperial (feet, inches, ounces, etc.) system of measurement; and the various and anachronistic aspects of the internal organisation of any government (e.g., the American Electoral College).

Compare with cruft, flag day.