loosely fitting clothing appropriate for sleeping; typically pajamas. Tier 3s are preceeded by tier 2s and tier 1s - lounging attire and dress clothes respectively.
I am so fucking tired of this dinnner party; I can't wait to get home and chill in my tier 3s.
She was so hungover she didn't get out of her tier 3s for two days.
I answered the door in my tier 3s and told that sales guy to fuck off.
