- (immunology) the attraction between an antigen and an antibody
- (anthropology) kinship by marriage or adoption; not a blood relationship
- (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"
- 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"
- the force attracting atoms to each other and binding them together in a molecule;
"basic dyes have an affinity for wool and silk"
- inherent resemblance between persons or things
- a natural attraction or feeling of kinship;
"an affinity for politics" "the mysterious affinity between them" "James's affinity with Sam"
