Definitions of set in:
- verb: enter a particular state
Example: "Laziness set in"
- verb: blow toward the shore
Example: "That gale could set in on us with the next high tide"
- verb: become established
Example: "Winter has set in"
Example: "Laziness set in"
Example: "That gale could set in on us with the next high tide"
Example: "Winter has set in"