(1) In this Act, unless the context otherwise requires,—
(a) "agnate"—one person is said to be an "agnate" of another if the two are related by blood or adoption wholly through males;
(b) "cognate"—one person is said to be a "cognate" of another if the two are related by blood or adoption but not wholly through males;
(c) "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;
(d) "full blood", "half blood" and "uterine blood"—
(i) 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 by different wives;
(ii) 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 this clause "ancestor" includes the father and "ancestress" the mother;
(e) "heir" means any person, male or female, who is entitled to succeed to the property of an intestate under this Act;
(f) "intestate"—a person is deemed to die intestate in respect of property of which he or she has not made a testamentary disposition capable of taking effect;
(g) "marumakkattayam law" means the system of law embodying the principles of matrilineal descent;
(h) "nambudri law" means the system of law applicable to persons who would have been governed by the Madras Nambudri Act, 1932;
(i) "related" means related by legitimate kinship:
Provided that illegitimate children shall be deemed to be related to their mother and to one another, and their legitimate descendants shall be deemed to be related to them and to one another; and any word expressing relationship or denoting a relative shall be construed accordingly.
Legal Commentary & Landmark Judgments: Section 3
Section 3 provides foundational statutory definitions under HSA, establishing precise biological categories of consanguinity, agnates, cognates, and full blood, and defining the legal concept of an 'heir'.
In family inheritance disputes where claimants assert rights as agnates or cognates, prepare a clear genealogical tree (shajra) demonstrating whether the descent is traced wholly through males (agnates) or through at least one female link (cognates).