IPA: /ˈkʌʃənləs/
KK: /ˈkʌʃənləs/
Not having a soft pad or support to make something more comfortable.
The chair was cushionless, making it quite uncomfortable to sit on for long periods.
Cushionless → It is formed from "cushion" (from Old French *coissin*, meaning a soft pillow or pad) and "-less" (meaning without). The word "cushionless" means without a cushion or lacking cushioning.
Think of a 'cushion' as a soft pad and remember that 'cushionless' means lacking that softness.