kick in Informal
Meaning: If something kicks in, it starts to work or it starts to have an effect.Synonym: take effect
- kick in I took some pills for the pain and after about half an hour I could feel them kicking in.
- kick in The effect of last year's tax cuts should kick in soon and start boosting the economy.
This medicine will make your temperature go down, but it takes about an hour to kick in. It doesn't work