Before the examination, you must make sure that you attempt to improve your vocabulary through reading. You may read novels, the newspaper or any other English literature media especially the Classics. Most nationally circulated newspapers contain articles written in a decent level of language. This helps by letting you build context surrounding the words. When you see the word being used in a sentence, you form a background on the word, making it easier to guess its synonym.
Every time you come across a new word, you must look it up in the dictionary and thesaurus to make sure that word is well-understood and thus, well-memorised. You can even make sentences of your own or use mnemonics to remember the word.
Another way to guess the meaning of the word is through breaking down the word into its roots. For instance, ‘Ornithology’ may be split into ‘ornis’ which means ‘birds’ and ‘logos’ which means ‘study’ thus establishing that it is the study of birds.
You can maintain a diary or notebook to keep a record of all the new words. This notebook will then serve as a tool for quick revision as the examination day nears.
You may prefer learning words of a similar category together for better understanding. For example, the names of specialists maybe learnt together. For instance, cardiologist (heart specialist), neurologist (brain specialist) and ophthalmologist (eye specialist)
Practising a lot of exercises on synonyms and words with similar meanings can be advantageous. The more you rehearse, the better you become. After all, practice makes perfect.