relation definition

1. <mathematics> A subset of the product of two sets, R : A x B. If (a, b) is an element of R then we write a R b, meaning a is related to b by R. A relation may be: reflexive (a R a), symmetric (a R b => b R a), transitive (a R b & b R c => a R c), antisymmetric (a R b & b R a => a = b) or total (a R b or b R a).

See equivalence relation, partial ordering, pre-order, total ordering.

2. <database design> A table in a relational database.

1. The act of relating or telling; also, that which is related; recital; account; narration; narrative; as, the relation of historical events. "oet's relation doth well figure them." (Bacon)

2. The state of being related or of referring; what is apprehended as appertaining to a being or quality, by considering it in its bearing upon something else; relative quality or condition; the being such and such with regard or respect to some other thing; connection; as, the relation of experience to knowledge; the relation of master to servant. "Any sort of connection which is perceived or imagined between two or more things, or any comparison which is made by the mind, is a relation." (I. Taylor)

3. Reference; respect; regard. "I have been importuned to make some observations on this art in relation to its agreement with poetry." (Dryden)

4. Connection by consanguinity or affinity; kinship; relationship; as, the relation of parents and children. "Relations dear, and all the charities Of father, son, and brother, first were known." (Milton)

5. A person connected by cosanguinity or affinity; a relative; a kinsman or kinswoman. "For me . . . My relation does not care a rush." (Ld. Lytton)

6. The carrying back, and giving effect or operation to, an act or proceeding frrom some previous date or time, by a sort of fiction, as if it had happened or begun at that time. In such case the act is said to take effect by relation. The act of a relator at whose instance a suit is begun.

Synonyms: Recital, rehearsal, narration, account, narrative, tale, detail, description, kindred, kinship, consanguinity, affinity, kinsman, kinswoman.

Origin: F. Relation, L. Relatio. See Relate.