StarDict is a GUI dictionary software for Windows and Linux created by Hu Zheng that can be used to manage multiple dictionaries and lookup words in them. There is a console version too for folks who prefer that. The source code of this tool can be found here.
Install: Download the Windows installer from the homepage and install it.
Add dictionaries: StarDict does not come pre-installed with any dictionaries. Dictionary files need to be installed and many such dictionary files are available here. Download and unzip the dictionary file until you have a directory with
.dict.dz files inside it. Move this directory to the
C:\Program Files (x86)\StarDict\dic directory.
Lookup: Lookup a word and if it exists in the dictionaries you installed, it should be displayed. If the word exists in multiple dictionaries, then all of those definitions are displayed. The order of the dictionaries used for lookup can be changed in the settings.
Tried with: StarDict 126.96.36.199