slice, bed

爿 depicts a tree trunk which is cut in half, which is symmetrical to 片. After cut, the cut tree trunk has a flat surface, so the original meaning of 爿 is a wooden plank, but such meaning has been replaced by 版.On the other hand, a flat surface can allow someone or something to lie down, so 爿 also means bed or table, but such meaning has been replaced by 牀.