If you have a smartphone you can download the Hans Wehr (English Arabic) dictionary for free. It is searchable! You have to look under Arabic Almanac. You find it also online. But it is based on roots.
just great is Aratools also online and an App for 15 dollars. It's Arabic English. You can write the word you search also with the article or the preposition, it gives you the root.
the best English Arabic English dictionary is the al Mawreed. I bought the digital version for 30 dollars three years ago in the AppStore. It has the audio for every word, not a synthetic voice but a native speaker.
if you speak German bookeditor Langenscheidt has put online his great, Modern dictionary for free, to help for the integration of Syrian refugees . Langenscheidt.com
A good electronic Dic. for you. You can find an App for this Dic. on Google store.