A dictionary is completely different from a thesaurus. Both of them are useful in developing one's skills in English.
A dictionary is a commonly used book of words compiled by a lexicographer. A lexicographer is one who collects and compiles all the available words to form a dictionary. In short, he is the compiler of a dictionary. The word “lexico" actually refers to “words". A dictionary may not be only in English but in any language. The words in a dictionary are arranged in alphabetical order so that it is easy to find the required words. A dictionary generally has the following uses:
- To find the spelling of the word
- To know about the exact usage of the word
- To find out the meaning of the word
- To know the noun, adjective and adverbial forms of the word.
- To know the class to which the word belongs
- And finally to know the various derivatives of the word
The first English dictionary was compiled by Dr. Samuel Johnson in the year 1755 and about 50 years later in the year 1806 Noah Webster compiled the first American English dictionary. Even in India, there are different types of dictionaries like English to Tamil dictionary, Hindi to English dictionary, etc. Some of the common dictionaries that are used today are The Oxford English dictionary, Collin's Co-build English dictionary, etc.
On the other hand, a thesaurus is completely opposite to dictionary. According to the Concise Oxford Dictionary, “a thesaurus is a book that lists words in groups which have similar meaning and other related concepts". But according to IA Richards, a thesaurus is a book that consists of groups of words that have similar meaning and it is used to find out words whose meanings are known by us and the words are in the tip of our tongue. The first thesaurus was published by an English doctor named Peter Mark Roget in the year 1852.
A dictionary is used to find out words' meaning and their spellings. For example, if you have come across a word “foster" (meaning - develop) you need to search the word in the dictionary and there you can find out its meaning, pronunciation and the usage of the word.
A thesaurus is mostly used by various writers and researchers who use a variety of words in their articles and research papers rather that using the same word repeatedly which may sound dull and boring. To find out a group of words with the same meaning or the words related to a particular word, you may search the thesaurus in the index section having the meaning of the words you are looking for. For example, if you want to find out different words having the meaning “traveler" you may find out words like voyager, tourist, wanderer, adventurer, pilgrim, etc., in the thesaurus.