Idioms are widely used in English and yet their meaning is often difficult to guess. This new reference book contains around 7000 idioms current in British, American and Australian English today which are explained clearly and simply using a carefully controlled defining vocabulary. It demonstrates how idioms are used by giving thousands of example sentences based on the Cambridge International Corpus, and shows clear information on grammar and collocation. It also provides etymological information where appropriate to enable better understanding and to make idioms easier to learn and remember. A full index makes idioms easy to find. Additional learning aids are provided in the form of photocopiable exercises and theme panels which present idioms in groups according to their meaning or function. Guidance is also given on the most useful idioms to learn.