Ubuntu has built-in dictionary software that you can use to look words up. But you must be connected to internet in order to use this dictionary. But if you are online, then there are a lot of online dictionaries available on the internet. So sometimes, working offline, you might need to look up some words. In that case, you need an offline dictionary. Artha is an offline dictionary that you can install in your Ubuntu Box to work seamlessly without the need of being connected to internet.
Artha is a wordnet based offline dictionary. According to the official website, "Artha is a free cross-platform English thesaurus that works completely off-line and is based on WordNet. Stable releases for download are currently available for GNU/Linux, Microsoft Windows and Windows Phone 7" and "Artha is released under the GNU General Public License version 2; hence you are free to copy/redistribute it."
You can use hotkey 'ctrl+alt+w' to look up a word in Artha or to launch it. To look-up a word in Artha, just select the word and press the hotkey. This hotkey is configurable, i.e. you can use your own keyboard combination to use Artha.
Wordnet - Artha uses the cognitive and excellent wordnet Database.
Hot key Lookup - It pops up the meaning of the selected word when pre-set hot key combination is pressed.
Regular Expression support - Regular expressions such as wild cards, joker, character class, and limits can be used to look-up the items in the thesaurus.
Notifications - The balloon tips or passive notifications can be enabled in Artha. In this mode, no new window is popped up, and the work can be continued uninterrupted.
Suggestions - For the words that do not correctly match, it shows near-matched word suggestions.
Senses - Words can have more than one sense in different contexts. From the official website: "You might not know to which sense/definition of a word does a relative map to. In Artha, when you select a relative, its corresponding definition is scrolled to and highlighted for easy comprehension."
"For a given word, the possible relatives shown by Artha includes Synonyms, Antonyms, Derivatives, Pertainyms (Related Noun/Verb), Attributes, Similar Terms, Domain Terms, Entails (what verb entails doing), Causes (what a verb causes to), Hypernyms (is a kind of), Hyponyms (kinds), Holonyms (is a part of) and Meronyms (parts)."
Installing Artha to your Ubuntu system is very simple. In Ubuntu, it is already available in the repositories. Just issue the apt-get command as follows:
$ sudo apt-get install artha
[sudo] password for raghu:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
wordnet wordnet-base wordnet-sense-index
The following NEW packages will be installed:
artha wordnet wordnet-base wordnet-sense-index
0 upgraded, 4 newly installed, 0 to remove and 67 not upgraded.
Need to get 11.1 MB of archives.
After this operation, 37.9 MB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://in.archive.ubuntu.com/ubuntu/ precise/universe wordnet-base all 1:3.0-26.1 [8,751 kB] Get:2 http://in.archive.ubuntu.com/ubuntu/ precise/universe wordnet i386 1:3.0-26.1 [63.5 kB] Get:3 http://in.archive.ubuntu.com/ubuntu/ precise/universe artha i386 1.0.2-1ubuntu1 [67.6 kB] Get:4 http://in.archive.ubuntu.com/ubuntu/ precise/universe wordnet-sense-index all 1:3.0-26.1 [2,235 kB] Fetched 11.1 MB in 6min 48s (27.2 kB/s)
Selecting previously unselected package wordnet-base.
(Reading database ... 145370 files and directories currently installed.)
Unpacking wordnet-base (from .../wordnet-base_1%3a3.0-26.1_all.deb) ...
Selecting previously unselected package wordnet.
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Selecting previously unselected package wordnet-sense-index.
Unpacking wordnet-sense-index (from .../wordnet-sense-index_1%3a3.0-26.1_all.deb) ...
Processing triggers for man-db ...
Processing triggers for bamfdaemon ...
Processing triggers for desktop-file-utils ...
Processing triggers for gnome-menus ...
Setting up wordnet-base (1:3.0-26.1) ...
Setting up wordnet (1:3.0-26.1) ...
Setting up artha (1.0.2-1ubuntu1) ...
Setting up wordnet-sense-index (1:3.0-26.1) ...
Processing triggers for libc-bin ...
ldconfig deferred processing now taking place
In other systems, where Artha is not present in the repositories, it can be installed with PPA. This PPA can be added with the command:
$ sudo apt-add-repository ppa:legends2k/artha
Accept it by pressing return when prompted. Now update the package information and install in the usual way:
$ sudo apt-get update
$ sudo apt-get install artha