Source: The Great Interpretation of Dreams (Ibn Sirin)
The niqab in a dream for a woman indicates her modesty, religion, and husband. Uncovering it indicates lack of modesty or separation from the husband.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
The niqab indicates covering and chastity. For a man, it indicates hiding a matter.
Source: Signs in the Science of Expressions (Ibn Shaheen)
The niqab is interpreted as covering. Whoever sees himself wearing it will attain covering.