an existing connection; a significant association between or among things

the relation between cause and effect.

relations,

the various connections between peoples, countries, etc.

foreign relations.

the various connections in which persons are brought together

business and social relations.

sexual intercourse.

the mode or kind of connection between one person and another, between an individual and God, etc.

connection between persons by blood or marriage.

a person who is related by blood or marriage; relative

his wife's relations.

the act of relating, narrating, or telling; narration.

Law . a principle whereby effect is given to an act done at one time as if it had been done at a previous time.

Mathematics .

a property that associates two quantities in a definite order, as equality or inequality.

a single- or multiple-valued function. ?

in or with relation to

with reference to; concerning

It's best to plan with relation to anticipated changes in one's earnings.

noun

alienage , irrelation

noun

affiliation , affinity , alliance , association , consanguinity , kin , kindred , kinship , kinsperson , liaison , propinquity , relationship , relative , sibling , similarity , connection , correlation , interconnection , interdependence , interrelationship , link , linkage , tie-in , kinsman , kinswoman , account , bearing , bond , cognation , correspondence , detail , family , filiation , narration , narrative , ratio , recital , reference , relevancy , report , telling