There many Ar-Eng dictionaries, in this article, I have chosen simple ones supporting the morpghological aspect of Arabic, and depending on the platform and the online/offline availability.

VerbAce

• Offline versions : Windows (trial version but crackable) | Android (free)

ArTools :

Features

• Prefix and suffix morphology.
• Shows POS information
• Over 80000 stems in dictionary.
• Especially suited for translating arabic news sources or for Arabic language learners.
• Crossplatform.

Download

• Online version : Website (free)
• Offline version : Windows (free) | Mac (free) | Android (payant) | iOS (payant)