Dream Symbols in The Dream Encyclopedia

by James R. Lewis and Evelyn Dorothy Oliver
Collars represent confinement and restraint (e.g., to “collar” someone). They also indicate completing or finishing something, as in putting the collar on a garment. Collars often are an indication of control (e.g., prisoners) or a token of subservience (e.g., slaves).

This kind of dream may well describe a frustrated work situation or a confining relationship.

Strangest Dream Explanations

by Dream Explanations - Anonymous
Dreams of a collar symbolize power, control, passive/aggressive behavior, and a desire to take the lead.

If you are wearing the collar, then you are submitting to someone’s will.

If you are leading someone else, then you are taking the lead and asserting dominance over someone.

Ten Thousand Dream Interpretation

by Gustavus Hindman Miller
To dream of wearing a collar, you will have high honors thrust upon you that you will hardly be worthy of.

For a woman to dream of collars, she will have many admirers, but no sincere ones, She will be likely to remain single for a long while.