contesseration (n.)

"harmonious assemblage, friendly union," 1610s, from Late Latin contesserationem (nominative contesseratio), noun of action from past-participle stem of contesserare "contact friendship by means of square tablets," from assimilated form of com "with, together" (see con-) + tessera "a die, cube, square tablet with writing on it" used as a token or ticket, from Ionic Greek tessera, neuter of tesseres  "the numeral four" (from PIE root *kwetwer- "four"). Latin tessera hospitalis was "a die broken between host and guest, kept as a means of recognition."