Definition of relative expands family relationships for tax provisions, affecting related-party tests and deduction eligibility. Definition of 'Relative' for Income-tax purposes identifies categories treated as familial: clause (41) of section 2 includes husband, wife, brother, sister and any lineal ascendant or descendant. The Explanation to section 13 expands to include spouse, siblings of the individual and spouse, lineal ascendants and descendants of both, spouses of those relatives, and lineal descendants of a brother or sister of either. For section 80E(3)(e) the category is confined to the spouse and children or the student for whom the individual is legal guardian.