Definition of kick in

The phrase "kick in" originated in the late 1960s, particularly in the context of drug culture. It initially referred to the sharing of money or resources among a group of people to help fund drug purchases or experiments. The term "kick" was already in common use among drug users, particularly in reference to the initial euphoric rush or "high" that a drug supplied. By adding the phrase "kick in," users were signifying that they were contributing money or goods to add to the communal pool that would subsequently "kick in" and provide the desired drug experience. As drug culture became more mainstream in the following decades, the meaning of "kick in" has evolved. It began to be used more broadly to signify a wide variety of contributions or payments, whether financial, material, or otherwise, particularly in situations where a group of people are working together toward a common goal. In summary, "kick in" began as a drug slang term and has since expanded to encompass more general ideas of shared contributions and benefits.