IPA: /ʌnˈpædɪd/
KK: /ʌnˈpædɪd/
Not having any extra material or cushioning added to it.
The unpadded chair was uncomfortable to sit on for long periods.
Unpadded → It is formed from "un-" (meaning not) and "padded" (from the verb "pad", which comes from Middle English *padden*, meaning to stuff or fill). The word "unpadded" means not stuffed or filled, indicating something that lacks padding.
Think of 'not' ('un-') having 'stuffing' ('padded') — that's why unpadded means something that is not stuffed.