Wrapper script is a script that wraps another script or command to provide extra functionalities or just to make something less tedious.
For example, the actual egrep in new GNU/Linux system is being replaced by a wrapper script named egrep. This is how it looks:
#!/bin/sh
exec grep -E "$@"
So, when you run egrep in such systems, you are actually running grep -E with all the arguments forwarded.
In general case, if you want to run an example script/command exmp with another script mexmp then the wrapper mexmp script will look like:
#!/bin/sh
exmp "$@" # Add other options before "$@"
# or
#full/path/to/exmp "$@"