As you feel confident with LookUp as a tool, you might want to import your legacy terminology.

LookUp offers two ways of importing data.
You can copy terminology from a list created with Mircosoft Word to the Windows clipboard (Ctrl-C) and insert them in LookUp (Functions).

Or you can use the LookUp Import Wizard to create entries from Excel or Access.
Check if project and subject are set correctly beforehand.

Exporting to MS Word or other formats is just as easy.