Handmark Oxford American Dictionary and Thesaurus SD/MMC ...

• This latest edition of the Dictionary features hundreds of new words and phrases - Abenaki, burka, cargo pants, 9/11, tankini, weaponize and more
• Full pronunciation guides, with recently viewed word lists for quick recall
• The Oxford American Desk Thesaurus offers you more than 175,000 synonyms, compound terms, idioms and more -- broken down in an easy-to-search format
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OK if you are in high school, maybe.:
I grant that my vocabulary is larger than average, but I seem to know every word in this dictionary. Words that I do not know are not in it. If you have graduated from college, I don't think it would be much use. The thesaurus gives only a few alternatives and it gives you no idea of what word would be the better choice, so it is not much use.

It's worth the trouble of installing on your PDA:
This is a very handy little dictionary. It's not meant to be the complete Oxford English Dictionary with every word in it. But it does the average job you expect from any good paperback dictionary. With my pocket pc near by I find reading a book less of a chore when there's a quick way to look up words I'm uncertain of. However, I had a lot of trouble getting the dictionary installed on my own SD Card. There was an SD CARD that came with the package but I had to remove my own SD card and insert this one before I could use the dictionary. This completely takes all the convenience out of using a PDA while reading a book or magazine. It took me a number of exchanges over a few days with Handmark's Support technicians to get it to work on my own SD. I had trouble explaining the problem in an e-mail and we went around and around a bit. But they were prompt in answering each followup question and very considerate. Most importantly, they got it working. The only other dictionary out there that works on my HP Pocket PC (IPAQ) is Merriam-Webster's Collegiate Dictionary and Franklin Thesaurus. But it only works if you use the SD Card that comes with the package. And the company will not let you download it to your own SD Card. Believe me, I tried. So stick with Handmark's Oxford.