The meaning of includes used in section 2(24),17, 11 of the Income Tax Act is not defined in the act itself. But we can take guidance from decisions by various high courts. Here is an excerpt of the court’s order in which the Hon’ble High Court tried to explain the meaning of includes.
Meaning of includes
The phrase ‘include’ used in section 2(24),17, 11 of the Income Tax Act came up before Hon’ble ITAT-Allahabad in Asstt. CIT Vs. Baldev Plaza  93 ITD 579 (ALL.-TRIB.) and it explained.
The phrase ‘include’ used in section 2(24),17, 11 of the Income Tax Act came up before various high courts as detailed under :
1. Hon’ble Kolkata High Court explained the meaning of “include” while delivering judgment in CIT/CWT V. P.R.S. Oberoi  52 TAXMAN 267/183 ITR 103 (CAL.) as under :
Meaning: The word ‘includes’ is often used in interpretation clauses in order to enlarge the meaning of the words or phrases occurring in the body of the statute.
2. Hon’ble Allahabad High Court explained the meaning of “include” while delivering judgment in All India Defence Accounts Association Vs. Union Of India  175 ITR 494 (ALL.) as under :
Meaning: The word ‘includes’ is generally used as a word of extension, but the meaning of a word or phrase is extended when it is said to include things that would not properly fall within its ordinary connotation. Thus, where ‘includes’ has an extending force, it adds towards the phrase a meaning which does not naturally belong to it. Scope of inclusive definition cannot be restricted to those words only which occur in such definition, but inclusive definition will extend to so many other things, which are not talked of in the section.
3. Hon’ble Ahmedabad High Court explained the meaning of “include” while delivering judgment in Gujarat Industrial Development Corpn. Vs. Asstt. CIT  129 ITD 73/138 TTJ 714) as under :
Meaning: The word ‘includes’ occurring in section 11(4) means that there is a reference of a property or a business of a trust which is a business undertaking in addition to the other properties of the trust.
Section 2(24), 11, 17 of Income Tax Act
(24) “income” includes—
(i) profits and gains ;
(ii) dividend ;
(iia) voluntary contributions received by a trust created wholly or partly for charitable or religious purposes or by an institution established wholly or partly for such purposes or by an association or institution referred to in clause (21) or clause (23), or by a fund or trust or institution referred to in sub-clause (iv) or sub-clause (v) or by any university or other educational institution referred to in sub-clause (iiiad) or sub-clause (vi) or by any hospital or other institution referred to in sub-clause (iiiae) or sub-clause (via) of clause (23C) of section 10 or by an electoral trust.
Explanation.—For the purposes of this sub-clause, “trust” includes any other legal obligation ;
(iii) the value of any perquisite or profit in lieu of salary taxable under clauses (2) and (3) of section 17;
(iiia) any special allowance or benefit, other than perquisite included under sub-clause (iii), specifically granted to the assessee to meet expenses wholly, necessarily and exclusively for the performance of the duties of an office or employment of profit ;
(iiib) any allowance granted to the assessee either to meet his personal expenses at the place where the duties of his office or employment of profit are ordinarily performed by him or at a place where he ordinarily resides or to compensate him for the increased cost of living ;
(iv) the value of any benefit or perquisite, whether convertible into money or not, obtained from a company either by a director or by a person who has a substantial interest in the company, or by a relative of the director or such person, and any sum paid by any such company in respect of any obligation which, but for such payment, would have been payable by the director or other person aforesaid ;
(iva) the value of any benefit or perquisite, whether convertible into money or not, obtained by any representative assessee mentioned in clause (iii) or clause (iv) of sub-section (1) of section 160 or by any person on whose behalf or for whose benefit any income is receivable by the representative assessee (such person being hereafter in this sub-clause referred to as the “beneficiary”) and any sum paid by the representative assessee in respect of any obligation which, but for such payment, would have been payable by the beneficiary ;
(v) any sum chargeable to income-tax under clauses (ii) and (iii) of section 28 or section 41 or section 59;
(va) any sum chargeable to income-tax under clause (iiia) of section 28;
(vb) any sum chargeable to income-tax under clause (iiib) of section 28;
(vc) any sum chargeable to income-tax under clause (iiic) of section 28;
(vd) the value of any benefit or perquisite taxable under clause (iv) of section 28;
(ve) any sum chargeable to income-tax under clause (v) of section 28;
(vi) any capital gains chargeable under section 45;
(vii) the profits and gains of any business of insurance carried on by a mutual insurance company or by a co-operative society, computed in accordance with section 44 or any surplus taken to be such profits and gains by virtue of provisions contained in the First Schedule ;
(viia) the profits and gains of any business of banking (including providing credit facilities) carried on by a co-operative society with its members;
(viii) [Omitted by the Finance Act, 1988, w.e.f. 1-4-1988. Original sub-clause (viii) was inserted by the Finance Act, 1964, w.e.f. 1-4-1964;]
(ix) any winnings from lotteries, crossword puzzles, races including horse races, card games and other games of any sort or from gambling or betting of any form or nature whatsoever.
Explanation.—For the purposes of this sub-clause,—
(i) “lottery” includes winnings from prizes awarded to any person by draw of lots or by chance or in any other manner whatsoever, under any scheme or arrangement by whatever name called;
(ii) “card game and other game of any sort” includes any game show, an entertainment programme on television or electronic mode, in which people compete to win prizes or any other similar game ;
(x) any sum received by the assessee from his employees as contributions to any provident fund or superannuation fund or any fund set up under the provisions of the Employees’ State Insurance Act, 1948 (34 of 1948), or any other fund for the welfare of such employees ;
(xi) any sum received under a Keyman insurance policy including the sum allocated by way of bonus on such policy.
Explanation.—For the purposes of this clause*, the expression “Keyman insurance policy” shall have the meaning assigned to it in the Explanation to clause (10D) of section 10;
(xii) any sum referred to in clause (va) of section 28;
(xiia) the fair market value of inventory referred to in clause (via) of section 28;
(xiii) any sum referred to in clause (v) of sub-section (2) of section 56;
(xiv) any sum referred to in clause (vi) of sub-section (2) of section 56;
(xv) any sum of money or value of property referred to in clause (vii) or clause (viia) of sub-section (2) of section 56;
(xvi) any consideration received for issue of shares as exceeds the fair market value of the shares referred to in clause (viib) of sub-section (2) of section 56;
(xvii) any sum of money referred to in clause (ix) of sub-section (2) of section 56;
(xviia) any sum of money or value of property referred to in clause (x) of sub-section (2) of section 56;
(xviib) any compensation or other payment referred to in clause (xi) of sub-section (2) of section 56;
(xviii) assistance in the form of a subsidy or grant or cash incentive or duty drawback or waiver or concession or reimbursement (by whatever name called) by the Central Government or a State Government or any authority or body or agency in cash or kind to the assessee other than,—
(a) the subsidy or grant or reimbursement which is taken into account for determination of the actual cost of the asset in accordance with the provisions of Explanation 10 to clause (1) of section 43; or
(b) the subsidy or grant by the Central Government for the purpose of the corpus of a trust or institution established by the Central Government or a State Government, as the case may be;