Hotclick
In the Opera web browser, Hotclick refers to double-clicking any word in a page.
HotClick can be enabled by going to Opera’s Accessibility Preferences (alt + p, then Accessibility.) It was introduced in Opera version 6.
Hotclick gives access to all search engines in Opera as defined by search.ini file, as well as giving access to the built-in translation, encyclopedia, and dictionary.
In addition to this, the Hotclick menu also gives access to the 'copy text', 'copy to note' (Opera 7 and later), and 'Send by email' functions.
Using Hotclick is the fastest way to search for a word in Opera.
Like all other menus, it can be customized in Opera 7 by using a custom menu ini file.