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