Dict: strongs - episun
Strongs:
G1996 @ ἐπισυνάγω episunagō ep-ee-soon-ag'-o From G1909 and G4863; to collect upon the same place: - gather (together).
G1997 @ ἐπισυναγωγή episunagōgē ep-ee-soon-ag-o-gay' From G1996; a complete collection; specifically a Christian meeting (for worship): - assembling (gathering) together.
G1998 @ ἐπισυντρέχω episuntrechō ep-ee-soon-trekh'-o From G1909 and G4936; to hasten together upon one place (or a particular occasion): - come running together.