Complete Dictionary of Dreams

by Dr. Mıchael Lennox
You may want to keep some of your thoughts hidden.

A hat covers the head, the symbolic representation of your thoughts. Wordplay using “cap” as synonymous for something that limits or contains means this particular type of head gear is likely pointing to a desire to limit or restrain your thoughts in some way.

A cap may also point to a desire to connect to your sportier nature, as caps were originally designed for outdoor play, where blocking the sun was desirable.

A cap in a dream might point to wishing to limit how much light you can see.

(See Hat.) 

Little Giant Encyclopedia

by Klaus Vollmar
Hat. Consciousness and thinking. Are you living too much in your head? It also addresses the fact that you keep something hidden or that something seems to be hidden.

The verb “to cap” also points to completion, the end of a situation. In fables and fairy tales, the cap often plays a significant role as a magical covering for the head, allowing the person to become invisible. It also points to the fact that you may be too visible. Or that you might pay more attention to yourself and be more outgoing.

See Shadow.

Folklore: Unhappy love.

Islamic Dream Interpretation

by Ibn Seerin
(Overseas cap, Persian toga, Roman toga, Shawl) In a dream, a cap means travels, a wife who is supporting her husband, or a husband who is supporting his wife.

A shawl-like attire that is worn over the head and shoulders in a dream represents honor, valor, a new trade, travel, a brother or a father. Taking off a cap in a dream means losing one’s authority or loss of his wealth.

A torn cap in a dream means the death of one’s brother or father. Wearing a cap in a dream also means repayment of one’s debts.

(Also see Coat, Overcoat)