fraternization(n = noun.act) fraternisation - associating with others in a brotherly or friendly way; especially with an enemy;
is a kind of association
Derived form verb fraternize₁

   The act of fraternizing or uniting as brothers. [1913 Webster]
"I hope that no French fraternization . . . could so change the hearts of Englishmen." [1913 Webster]

N  friendship, amity, friendliness, brotherhood, fraternity, sodality, confraternity, harmony, peace, firm friendship, staunch friendship, intimate friendship, familiar friendship, bosom friendship, cordial friendship, tried friendship, devoted friendship, lasting friendship, fast friendship, sincere friendship, warm friendship, ardent friendship, cordiality, fraternization, entente cordiale, good understanding, rapprochement, sympathy, fellow-feeling, response, welcomeness, affection, favoritism, good will, acquaintance, familiarity, intimacy, intercourse, fellowship, knowledge of, introduction, friendly, amicable, amical, well-affected, unhostile, neighborly, brotherly, fraternal, sympathetic, harmonious, hearty, cordial, warm- hearted, friends with, well with, at home with, hand in hand with, on good terms, on friendly terms, on amicable terms, on cordial terms, on familiar terms, on intimate terms, on good footing, on speaking terms, on visiting terms, in one's good graces, in one's good books, acquainted, familiar, intimate, thick, hand and glove, hail fellow well met, free and easy, welcome, amicably, with open arms, sans ceremonie, arm in arm, amicitia semper prodest, a mystic bond of brotherhood makes all men one, friendship is love without either flowers or veil, trulgus amicitias utilitate probat.