law: Hindu Marriage Act, 1955
  1. Definitions.-
  In this Act, unless the context otherwise requires,-
  (a) the expressions "custom" and "usage"
  
  signify any rule which, having been continuously and uniformly observed for a
  
  long time, has obtained the force of law among Hindus in any local area, tribe,
  
  community, group or family:
  Provided that the rule is certain and not unreasonable
  
  or opposed to public policy; and
  Provided further that in the case of a rule applicable
  
  only to a family it has not been discontinued by the family;
  (b) "district court" means, in any area for which
  
  there is a city civil court, that court, and in any other area the principal
  
  civil court of original jurisdiction, and includes any other civil court which
  
  may be specified by the State Government, by notification in the Official
  
  Gazette, as having jurisdiction in respect of the matters dealt with in this
  
  Act;
  (c) "full blood" and "half blood"-two
  
  persons are said to be related to each other by full blood when they are
  
  descended from a common ancestor by the same wife and by half blood when they
  
  are descended from a common ancestor but by different wives;
  
  
  (d) "uterine blood"- two persons are said to be related to each other
  
  by uterine blood when they are descended from a common ancestress but by
  
  different husbands;
  Explanation.- In clauses (c) and (d), "ancestor"
  
  includes the father and "ancestress" the mother;
  (e) "prescribed" means prescribed by rules made under
  
  this Act;
  (f) (i) "sapinda relationship" with reference to any
  
  person extends as far as the third generation (inclusive) in the line of ascent
  
  through the mother, and the fifth (inclusive) in the line of ascent through the
  
  father, the line being traced upwards in each case from the person concerned,
  
  who is to be counted as the first generation;
  (ii) two persons are said to be
  
  "sapindas" of each other if one is a lineal ascendant of the other
  
  within the limits of sapinda relationship, or if they have a common lineal
  
  ascendant who is within the limits of sapinda relationship with reference to
  
  each of them;
  (g) "degrees of prohibited relationship"-two persons
  
  are said to be within the "degrees of prohibited relationship"-
  (i) if one is a lineal ascendant of the other;
  
  or
  (ii) if one was the wife or husband of a
  
  lineal ascendant or descendant of the other; or
  (iii) if one was the wife of the brother or of
  
  the father's or mother's brother or of the grandfather's or grandmother's
  
  brother of the other; or
  (iv) if the two are brother and sister, uncle
  
  and niece, aunt and nephew, or children of brother and sister or of two
  
  brothers or of two sisters;
  Explanation. - For the purposes of clauses (f) and (g),
  
  relationship includes-
  (i) relationship by half or uterine blood as well as by full
  
  blood;
  (ii) illegitimate blood relationship as well as legitimate;
  (iii) relationship by adoption as well as by blood and all terms
  
  of relationship in those clauses shall be construed accordingly.