word defined is said to mean a certain thing, it is possible for the word to have a somewhat different meaning in the different Sections of the Act depending upon the subject or the context. That is why all definitions in Statutes, generally, begin with the qualifying words, namely, “unless there is anything repugnant in the subject or context”. (The Vanguard Fire and General Insurance Co. Ltd. Madras v. Fraser & Ross, AIR 1960 SC 971). There may be Sections in the Act where the meaning may have to be departed from, on account of the subject or context in which the word has been used, and that will be giving effect to the opening sentence in the definition section, namely, “unless there is anything repugnant in the subject or context”. A definition is not to be read in isolation. It must be read in the context of the phrase which it defines, realising that the function of a definition is to give precision and certainty to a word or phrase which would otherwise be vague and uncertain but not to contradict it or supplant it altogether. (Hotel and Catering Industry Training Board v. Automobile Proprietary Ltd, [1968] 1 WLR 1526; and A. Rajappa, (1978) 2 SCC213; Subramanian Swamy v. State of Uttarakhand, 2020 SCC OnLine Utt 329).If the context and effect of the relevant provisions is repugnant to the application of the said rule of construction, assistance of the said section cannot be invoked. (State of Bihar v. D.N. Ganguly, 1958 SCC OnLine SC 48; Venkatrayapuram Industrial Area Township v. Govt. of A.P., 2014 SCC OnLine Hyd 707). The definition of „ Availability‟ as given in the MYT Regulations 2015 is used for the purpose of calculating availability of existing transmission system for paying Normative Tariff and incentives or disincentives and can not therefore used in regulation 47 of RE regulations 2013.