Definition of "Affinity" :
noun: a natural attraction or feeling of kinship
"An affinity for politics."
noun: inherent resemblance between persons or things
noun: the force attracting atoms to each other and binding them together in a molecule
"Basic dyes have an affinity for wool and silk."
noun: (immunology) the attraction between an antigen and an antibody
noun: a close connection marked by community of interests or similarity in nature or character
"Found a natural affinity with the immigrants."
noun: (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."
noun: (anthropology) kinship by marriage or adoption; not a blood relationship