JCL or job control language is an essential part of mainframe computing. It is used to define and execute batch jobs that automate various tasks related to data processing. There are several synonyms for JCL that are commonly used in the mainframe industry. Some of these include batch language, job script, and job language. Batch language refers to the code used to define and execute batch jobs on a mainframe system. Job script is another term used to describe the set of instructions used to execute a batch job. Job language is yet another synonym used to refer to JCL, which is used mainly to automate data processing tasks on a mainframe.