Mat 18:20 For where two or three are gathered together in my name, there am I in the midst of them.

"Gathered" is from sunago, (sunagô) which means "to bring together," "join," "collect," "unite," and "gather together." Matthew uses to indicate the general bringing together of things with the sense of uniting them. This is the unselective sense of gathering as contrasted with sullego, also translated as "to gather" but which means a selective gathering, a picking particular things as opposed to bringing together everything.

"Name" is from onoma, which means "name." It means both the reputation of "fame," but it also means "a name and nothing else," as opposed to a real person. Christ usually used it to refer to the Father, whose unspoken name is translated from the Hebrew as "I am who I," but in the original can be read in a number of interesting ways include "the existence of existence," the "existing being," and similar ideas. These name captures both the idea that God truly exists and He is the foundation of existence and the base of the true reality.