Indian file

1. noun A line one person or one thing in width; single file. One of many expressions often considered offensive for making reference to Native American stereotypes or tropes. An Indian file of geese—such an unusual flight pattern for the bird—crossed overhead as we traversed the field.

2. adverb In such a line. The students lined up and walked Indian file into the auditorium.

(in) single/Indian ˈfile

in a line, one person after another: The whole class walked along behind the teacher in single file.When American Indians walked in a group, each person walked in the footsteps of the person in front so that they could not be counted by the enemy.