- sweats
- sweat pants, shirt, suits
- bummers
- scrubbies
- grubs
- snuggies
- casual clothes
- leisure clothes, wear
- lounge wear
- lounging clothes
- around the house cloths
- inside clothes
- knocking around clothes
- my best clothes
- fat pants
The Japanese, of course, have one and only one word for such clothes. These people have one word for every kind of situation. Very scientific but you sure gotta remember a lot!