batt
/bæt/noun
1- a piece of felted material used for lining or insulating items such as quilts and sleeping bags（被子或睡袋内衬的）棉胎。
1.1
- a piece of fibreglass used to insulate buildings（房屋绝缘用的）玻璃棉。
词源
late Middle English （in the general sense 'lump， piece'）： of unknown origin.