This function is to combine two word libraries on the same topic into
one word library. You can only merge word
libraries, NOT
shorthand libraries.
Select "Library Management->Merge Libraries..." from the main menu
and you will see a dialog. You need choose the first source library and the second source
library. The target library is optional. If it's left blank, the second source
library will be used as the target library. That means the first library is
merged into the second library.