bunch_up
1. [ verb ] form into a bunch
Synonyms: bunch bunch_together
Examples:

"The frightened children bunched together in the corner of the classroom"

Related terms: cluster bunch
2. [ verb ] gather or cause to gather into a cluster
Synonyms: cluster bunch clump bundle
Examples:

"She bunched her fingers into a fist" "The students bunched up at the registration desk"

Related terms: form agglomerate bunch package bundle