Source: The Great Interpretation of Dreams (Ibn Sirin)
Breaking a spear in a dream indicates the death of a child or brother, or weakness.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Breaking a spear indicates removal from authority or failure.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Breaking a spear is interpreted as worry and calamity concerning a child.