From Wiktionary, the free dictionary
From mattress + -y.
mattressy (comparative more mattressy, superlative most mattressy)
- (informal) Resembling or characteristic of a mattress; large, soft, and yielding.
2008, James Slater, Like Phosphorescent Desert Buttons, page 98:“You try it Mister, and so help me God I will make sure you spend the rest of your non-adult life bouncing off the mattressy walls of a psych ward.”
