The Collaborative International Dictionary of English v.0.48:

Kith \Kith\ (k[i^]th), n. [OE. kith, cu[eth], AS.
   c[=y][eth][eth]e, c[=y][eth], native land, fr. c[=u][eth]
   known. [root]45. See Uncouth, Can, and cf. Kythe.]
   Acquaintance; kindred.
   [1913 Webster]

         And my near kith for that will sore me shend. --W.
                                                  Browne.
   [1913 Webster]

         The sage of his kith and the hamlet.     --Longfellow.
   [1913 Webster]

   Kith and kin, kindred more or less remote.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "kith and kin":
   agnate, ancestry, blood, blood relation, blood relative, clansman,
   cognate, collateral, collateral relative, connections,
   consanguinean, distaff side, distant relation, enate, family,
   flesh, flesh and blood, folks, german, kin, kindred, kinfolk,
   kinnery, kinsfolk, kinsman, kinsmen, kinswoman, near relation,
   next of kin, people, posterity, relations, relatives, sib, sibling,
   spear kin, spear side, spindle kin, spindle side, sword side,
   tribesman, uterine kin