gatefold

名词 gatefold:

1. an oversize page that is folded in to a book or magazine
   同义词：foldout

gate.fold

n.Printing （名词）【印刷术】
A foldout, especially one that opens to double the page size.
折叠插页：一张插页，尤指打开的使纸张的尺寸扩大为原来的两倍的插页