BEWARE OF THE THESAURUS!

A piece of writing can be dull if adjectives are used repeatedly. We can use a thesaurus to add variation to our writing; however, this should be used with caution as no two words have exactly the same meaning.

Here's an example; you are writing a scientific paper and you want to describe the performance of a catalyst. You want to find an alternative to 'good' and 'excellent' because you have used those words a few times already.

You get out your thesaurus (or access one online) and discover that 'distinguished' is a synonym of 'excellent', so you write,

"X gives a distinguished performance as a catalyst for . . . "

Unfortunately, this is not quite right. As an adjective, 'distinguished' is normally used to describe people. The Collins online dictionary defines 'distinguished' as,

1. noble or dignified in appearance or behaviour
2. eminent; famous; celebrated

http://www.collinsdictionary.com/dictionary/english/distinguished

A good strategy is to use a dictionary in combination with a thesaurus to make sure that a word is suitable for your purpose. Using Google to see how words are used in sentences can also be helpful.