noun
housedress; house clothes
Refers to comfortable clothing worn at home, distinct from going-out clothes or formal wear.
帰宅したらすぐに家庭着に着替える。
I change into house clothes as soon as I get home.
パジャマ specifically refers to sleepwear, whereas 家庭着 is general loungewear for home.
Compound of 家庭 (かてい, 'home, household') and 着 (ぎ, 'clothing').