lounge pants 

Pants that you lounge in

I wore my lounge pants to watch the game on television in.

lounge pants by Amberbishop226 August 6, 2019

loungy pants 

Comfy trousers usually of the pyjama or jogging variety put on for lounging around the house.

It's loungy pants time!

loungy pants by lyns81 August 1, 2010