The phrasal verb "kick in" is predominantly used in informal speech but can sometimes appear in semi-formal contexts, particularly when discussing processes or mechanisms starting or becoming active. It is commonly used to describe the onset of something, often an effect, function, or reaction, such as medicine's effects or machinery beginning to operate. For example, one might say, "The painkillers will kick in soon," indicating the moment when their effect becomes noticeable. It's also used metaphorically in contexts like funding or resources being activated or becoming available. "Kick in" is widely understood across different English-speaking regions and remains a versatile expression due to its broad applicability in describing starting points across various situations.
B1
Intermediate
1. To begin to take effect or to start working.
The medicine takes about an hour to kick in.
As soon as the caffeine kicks in, I'll start feeling more awake.
2. To contribute or provide something, usually money, to a group effort or project.
Each employee was asked to kick in $5 for the farewell gift.
The neighborhood residents kicked in to repair the playground equipment.