Dictionary.net

• gather or cause to gather into a cluster; "She bunched her fingers into a fist"; "The students bunched up at the registration desk"

2006 - WordNet 3.0
By Princeton University

• gather or cause to gather into a cluster; "She bunched her fingers into a fist"; "The students bunched up at the registration desk"

2011 - English Dictionary Database
By DataStellar Co., Ltd