Also found in: Dictionary, Thesaurus, Medical, Legal, Encyclopedia.
to begin; to become fixed for a period of time. A severe cold spell set in early in November. When high temperatures set in, the use of electricity went up considerably.
to begin If the wound is not treated, infection may set in. In winter, darkness sets in so early!
1. Insert, put in, as in I still have to set in the sleeves and then the sweater will be done. [Late 1300s]
2. Begin to happen or become apparent, as in Darkness was setting in as I left. [c. 1700]
3. Move toward the shore, said of wind or water, as in The tide sets in very quickly here. [Early 1700s]
1. To insert or fix something securely: The tailor patched my jacket and set in a new liner. I put the stakes in the ground and set them in with a mallet.
2. To become established as an internal or external condition, especially one that brings suffering or hardship to a person or group of people: Panic set in when the people realized the building was on fire. We must put a bandage on your wound before an infection sets in. We need wood for the fire now that winter is setting in.
3. To move toward the shore. Used of wind or water: After nightfall, the wind set in.