A logical or natural association between two or more things; relevance of one to another; connection: the relation between smoking and heart disease. The connection of people by blood or marriage; kinship. A person connected to another by blood or marriage; a relative. The way in which one person or thing is connected with another: the relation of parent to child. The mutual dealings or connections of persons, groups, or nations in social, business, or diplomatic matters: international relations. Sexual intercourse. Reference; regard: in relation to your inquiry. The act of telling or narrating. A narrative; an account. Law The principle whereby an act done at a later date is considered to have been done on a prior date.