ph.

1. (不好的事情)产生，开始，到来，恶化
If something unpleasant sets in, it begins and seems likely to continue or develop.

1. become established

e.g. winter has set in

2. enter a particular state

e.g. Laziness set in
After a few moments, the effects of the drug kicked in

Synonym: kick in

3. blow toward the shore

e.g. That gale could set in on us with the next high tide