In this Act, unless the context otherwise requires,--
         ¹ [(1) "advance surtax" means the Surtax payable under section 7A;]
         ² [(1A)] "assessee" means a person by whom surtax or any other sum of money is payable under this Act and includes every person in respect of whom any proceeding under this Act has been taken for the assessment of his chargeable profits or of the amount of refund due to him or of the chargeable profits of any other person in respect of which he is assessable or of the amount of refund due to such other person;
         (2) "assessment" includes re-assessment;
         (3) "assessment year" means the period of twelve months commencing on the 1st day of April, every year;
         (4) "Board" means the Central Board of Direct Taxes constituted under the Central Boards of Revenue Act, 1963 (54 of 1963);
         (5) "chargeable profits" means the total income of an assessee computed under the Income-tax Act, 1961 (43 of 1961) for any previous year or years, as the case may be, and adjusted in accordance with the provisions of the First Schedule;
         (6) "Income-tax Act" means the Income-tax Act, 1961 (43 of 1961);
         (7) "prescribed" means prescribed by rules made under this Act;
         ¹ [(7A) "regular assessment" means as assessment made under section 6;]
         (8) "statutory deduction" means an amount equal to ³ [fifteen per cent.] of the capital of the company as computed in accordance with the provisions of the Second Schedule, or an amount of two hundred thousand rupees, whichever is greater:
         Provided that where the previous year is longer or shorter than a period of twelve months, the aforesaid amount of ³ [fifteen per cent.] or, as the case may be, of two hundred thousand rupees shall be increased or decreased proportionately:
         Provided further that where a company has different previous years in respect of its income, profits and gains, the aforesaid increase or decrease, as the case may be, shall be calculated with reference to the length of the previous year of the longest duration; and
         (9) all other words and expressions used herein but not defined and defined in the Income-tax Act shall have the meanings respectively assigned to them in that Act.