The Collaborative International Dictionary of English v.0.48:

Relative \Rel"a*tive\ (r?l"?-t?v), a. [F. relatif, L. relativus.
   See Relate.]
   1. Having relation or reference; referring; respecting;
      standing in connection; pertaining; as, arguments not
      relative to the subject.
      [1913 Webster]

            I'll have grounds
            More relative than this.              --Shak.
      [1913 Webster]

   2. Arising from relation; resulting from connection with, or
      reference to, something else; not absolute.
      [1913 Webster]

            Every thing sustains both an absolute and a relative
            capacity: an absolute, as it is such a thing, endued
            with such a nature; and a relative, as it is a part
            of the universe, and so stands in such a relations
            to the whole.                         --South.
      [1913 Webster]

   3. (Gram.) Indicating or expressing relation; refering to an
      antecedent; as, a relative pronoun.
      [1913 Webster]

   4. (Mus.) Characterizing or pertaining to chords and keys,
      which, by reason of the identify of some of their tones,
      admit of a natural transition from one to the other.
      --Moore (Encyc. of Music).
      [1913 Webster]

   Relative clause (Gram.), a clause introduced by a relative
      pronoun.

   Relative term, a term which implies relation to, as
      guardian to ward, matter to servant, husband to wife. Cf.
      Correlative.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Relative \Rel"a*tive\, n.
   One who, or that which, relates to, or is considered in its
   relation to, something else; a relative object or term; one
   of two object or term; one of two objects directly connected
   by any relation. Specifically:
   (a) A person connected by blood or affinity; strictly, one
       allied by blood; a relation; a kinsman or kinswoman.
       "Confining our care . . . to ourselves and relatives."
       --Bp. Fell.
   (b) (Gram.) A relative pronoun; a word which relates to, or
       represents, another word or phrase, called its
       antecedent; as, the relatives "who", "which", "that".
       [1913 Webster]

WordNet (r) 3.0 (2006):

relative
    adj 1: estimated by comparison; not absolute or complete; "a
           relative stranger" [syn: relative, comparative] [ant:
           absolute]
    2: properly related in size or degree or other measurable
       characteristics; usually followed by `to'; "the punishment
       ought to be proportional to the crime"; "earnings relative to
       production" [syn: proportional, relative]
    n 1: a person related by blood or marriage; "police are
         searching for relatives of the deceased"; "he has distant
         relations back in New Jersey" [syn: relative, relation]
    2: an animal or plant that bears a relationship to another (as
       related by common descent or by membership in the same genus)
       [syn: relative, congener, congenator, congeneric]

Moby Thesaurus II by Grady Ward, 1.0:

114 Moby Thesaurus words for "relative":
   affiliated, affinitive, agnate, allied, analogical, analogous,
   ancestry, appertaining, applicable, approximate, apropos,
   associated, associative, aunt, blood, blood relation,
   blood relative, brother, child, clansman, cognate, collatable,
   collateral, collateral relative, commensurable, commensurate,
   comparable, comparative, conditional, congenial, connected,
   connections, connective, consanguinean, contingent, contingent on,
   correlative, cousin, daughter, dependent on, distaff side,
   distant relation, en rapport, enate, family, father, flesh,
   flesh and blood, folks, german, germane, grandchild, granddaughter,
   grandfather, grandmother, grandparent, grandson, half brother,
   interconnected, interrelated, kin, kindred, kinfolk, kinnery,
   kinsfolk, kinsman, kinsmen, kinswoman, kith and kin, linking,
   matchable, mother, much at one, near, near relation, nephew,
   next of kin, niece, parallel, parent, people, pertaining,
   pertinent, posterity, proportionable, proportional, proportionate,
   referable, referring, related, relating, relation, relational,
   relations, relative to, relatives, relevant, reliant, sib, sibling,
   similar, sister, son, spear kin, spear side, spindle kin,
   spindle side, subject to, subordinate to, sword side, sympathetic,
   tribesman, uncle, uterine kin



The Free On-line Dictionary of Computing (30 December 2018):

RELATIVE

   Early system on IBM 650.  Listed in CACM 2(5):16 (May 1959).


Bouvier's Law Dictionary, Revised 6th Ed (1856):

RELATIVE. One connected with another by blood or affinity; a relation, a
kinsman or kinswoman. In an adjective sense, having relation or connexion
with some other person or thing; as relative rights, relative powers.