Source: The Great Interpretation of Dreams (Ibn Sirin)
A laughing enemy in a dream indicates his gloating and the dreamer falling into calamity or worry.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A laughing enemy indicates worry and grief afflicting the dreamer.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A laughing enemy is interpreted as worry and calamity.