RDz includes a visible subset of CICS Explorer functionality.  I say a visible subset, because it actually includes ALL of CICS Explorer (and the 2 work great together).  In that RDz is geared towards developers, a decision was made to expose (by default) a subset of CICS Explorer that would be of greatest interest to Developers.  If, however, you are doing POC work, on a test system, or have some other scenario where you need the power of RDz AND the full power of CICS Explorer, this is simple to accomplish.

By default, your CICS/SM perspective will NOT include a MenuEntry for Definitions.  To show this entry is quite simple. 

• In RDz 9.1, simply go to  Window -> Preferences -> General -> Capabilities  and select  CICS System Administration
• If you are using RDz 8.x and this preference is not available, then you can simply add the following line to your eclipse.ini after -vmargs
  • -Dcom.ibm.cics.explorer.sm.ui.full.enable=true
     

Then you've got that great marriage of RDz development power and CICS Explorer Admin power ... like having brains and brawn in one package.