Dictionary of English Spelling by Martin Manser
The Wordsworth Dictionary of English Spelling is the only spelling dictionary to give concise meanings throughout, and the only full-size spelling dictionary to have boxed features on spelling rules. Quicker, clearer, and easier to use than a conventional dictionary, it includes the latest additions to the English language (for instance, new words such as helpline, karaoke, synergy and teleworking). It is also comprehensive - featuring 50,000 spellings at a glance; informative - with concise meanings given throughout, and helpful, with 175 panels showing spelling rules and tips.