The Civil Engineering Dictionary explains the meaning of words . Free!

features:

♦Offline ! No internet connection needed . The Internet is used only when a word is not found in the dictionary
♦You can browse through words with your finger!
♦ Voice Recognition
♦ Issues with the text color defined by the user
♦ Bookmarks and history
♦ random search button , useful for learning new words
♦ friendly interface and functional user
♦ Share your favorites definitions