Merriam-webster

Merriam-webster's Notebook Dictionary 1º edição

You're most likely to want a dictionary when you're reading or writing. Merriam-Webster's Notebook Dictionary gives you the reference information you need in a convenient, slim-line format that fits easily into your three-ring binder to give you language resources when and where you need them most. The dictionary has 40,000 entries for widely-used words.