"atsumete/集めて" is a flection of "atsumeru/集める" As 雲小泉 said,　it means "to gather, to collect." But it is exactly different from "atsumaru/集まる" "atsumeru" is vt, "atsumaru" is vi. e.g.) 先生は私たちを集めた。/The teacher gathered us. 私たちは先生の前に集まった。/We gathered around the teacher.

In addition to the above two answers, it should be "atsumatte" , not "atsumate". "Atsumatte! " means "Please gather! " in situations like a teacher calls the kids.

集まる(P); 集る(io) 【あつまる】 (v5r,vi) to gather; to collect; to assemble; 私達は先生の前に集まった。 We gathered around the teacher.[Amend] Can't find "atsumate".

Japanease letters are intersesting