IDIOMS

housewarming

(idiomatic) A party to celebrate moving into a new home.

Example: 1898, Winston Churchill, chapter 5, The Celebrity:
  In the eyes of Mr. Farquhar Fenelon Cooke the apotheosis of the Celebrity was complete. The people of Asquith were not only willing to attend the house-warming, but had been worked up to the pitch of eagerness.
The act of welcoming a person/family to their newly purchased or newly rented home.
  A housewarming gift.
2004, Jacob M Appel, “Gadney's Immunity”, Southwest Review, volume 89, number 4, page 580:
  They had their first argument on the evening Gadney moved in, their housewarming spat, he later called it.
2011, John Kinsella, The Offering:
  Fortunately, Dave had left them a packet of rollie tobacco and papers for a housewarming