Install Lingoes translator tool in Ubuntu/Linux ... or give it a try to a Linux native dictionary software: Goldendict

1) Install Wine Compatibility Layer (WineHQ):
winetricks should be also installed as default, if not also install winetricks.

2) Install Internet Explorer 7 via winetricks:
Open terminal and type "sh winetricks ie7" then follow the instructions.

3) Copy "mfc42u.dll" file to system and system32 folders:
http://www.dll-files.com/dllindex/dll-files.shtml?mfc42u

4) Download and install Lingoes translator tool (version 2.7.1 tested):
http://www.lingoes.net/en/translator/download.htm

5) Open "Internet Explorer" with Wine and edit "ActiveX Controls" settings:
Tools -> Internet Options -> Security
Click "Custom Level" for "Internet" zone and enable ActiveX Controls
Enable "Download signed ActiveX Controls"
Probably Internet Explorer will not be your default Internet browser in Linux, therefore security warnings due to those settings might not be so important.

6) You may also install the fonts like following way:
sh winnetricks fakejapanese
sh winnetricks fakekorean
sh winnetricks fakechinese

7) You can add speech functionality, if you like:
Go to http://www.lingoes.net/en/translator/speech.htm and follow the instructions.

Except hot-keys and text capturing from the screen Lingoes might work well.

GoldenDict:
GoldenDict is a great dictionary software and natively supported in Linux Distributions.

Supported dictionary files:

• Babylon .BGL files,
• StarDict .ifo/.dict./.idx/.syn dictionaries,
• Dictd .index/.dict(.dz) dictionary files, and more.

GoldenDict official website:
http://goldendict.org