Definitions
1.verbTo secure (someone or something) in a locked enclosure.
2.verbTo fix the value of something potentially variable."I've locked in a rate of 5%."
3.nounA sleepover party, usually held in a public place such as a church or school, in which the participants are not allowed to leave until the next morning."The youth group will have their annual lock-in this weekend."
4.nounAn illegal but widely-tolerated invitation-only gathering in a British pub, after the end of licensing hours, to allow regular customers the opportunity to enjoy further drinking time.
5.nounA situation in which members of an industry have agreed to adopt a certain standard and have retooled their production to meet this standard, thus making it very costly to change to a different standard.