Collins Pro English Dictionary by Ultralingua... Put the entire English language in your pocket with the Collins Pro English Dictionary for iPhone and iPod touch. Download this feature-rich dictionary of the English language, optimized for speed and ease of use on iPhone and iPod touch. Features:

• Over 141,500 references with fully developed definitions
• Automatic recognition of inflected forms (conjugations, plurals)
• Slang, technical language, and both UK and US spellings.
• Thousands of biographical and geographic entries
• Etymologies (word histories)
• Hundreds of usage notes about troublesome constructions
• Verb conjugation for all tenses
• IPA (International Phonetic Alphabet) pronunciations for most entries
• Number-to-text converter
• Easy tap-on-word feature to extend your search
• Search history
• Approximate search (in case you misspell or mistype!)
• Back and forward buttons

Collins Dictionaries, a division of HarperCollins, has published top-flight dictionaries since 1819. The Pro-level dictionary software, developed and distributed by Ultralingua, represents the cutting edge in dictionary data and software.