[n] inherent resemblance between persons or things
[n] a natural attraction or feeling of kinship; "an affinity for politics"; "the mysterious affinity between them"; "James's affinity with Sam"
[n] the force attracting atoms to each other and binding them together in a molecule; "basic dyes have an affinity for wool and silk"
[n] (immunology) the attraction between an antigen and an antibody
[n] a close connection marked by community of interests or similarity in nature or character; "found a natural affinity with the immigrants"; "felt a deep kinship with the other students"; "anthropology's kinship with the humanities"
[n] (biology) state of relationship between organisms or groups of organisms resulting in resemblance in structure or structural parts; "in anatomical structure prehistoric man shows close affinity with modern humans"
[n] kinship by marriage or adoption; not a blood relationship