Dictionary meaning/technical literature :
Apex court in Indo International Industries v. CST UP-AIR 1981 SC 1079 = (1981) 3 SCR 294 = 1981 (2) SCC 528 = 47 STC 359 = 8 ELT 325 (SC) – held “in interpreting items in statutes like Excise Tax Act, or sales tax act, where diverse products, articles and substances are classified, resort should be had, not to the scientific and technical meaning of terms and expressions used, but to their popular meaning i.e. the meaning attached to them by those dealing with them. If any term or expression has been defined in the enactment then it must be understood in the sense in which it is defined, otherwise common parlance or commercial parlance has to be obtained”.
In absence of any definition of any word or expression in statute, it would be permissible to refer to the dictionary meaning of that expression. – Star Paper Mills Ltd. V. CCE – 1989 (43) ELT 178 (SC).