concertina
/ˌkɔnsəˈti:nə; ˌkɑnsɚ`tinə/ n
musical instrument like a small accordion, consisting of a closed pleated tube, held in the hands and played by pressing the ends together to force air past reeds (reed 2) 六角手风琴. =>illus 见插图. concertina, v (pt, pp concertinaed, pres p concertinaing) [I]
fold up (as if) by being pressed together from each end （像）（从各端受挤压）摺起
The lorry had concertinaed after crashing into the tree. 卡车撞到大树後摺在一起.