Funeral
A funeral is the rite of ending and settling, so it is read — unexpectedly — as a good omen. It means old matters conclude and a new chapter opens, and tradition held that seeing the bier meant wealth coming in. Conducting someone else's funeral means there is a relationship or role you need to close out. If you have recently lost someone, though, this dream is better read as part of grieving than as a forecast.
A funeral is where an ending is confirmed and someone is sent off, so in dreams it means completion and putting things in order. It is one of the clearest examples of a symbol read against its appearance. Where a real bereavement is recent, though, the story changes.
Readings by Situation
Holding a funeral or seeing a bier
A favourable dream of old matters being tied off and a new phase opening. Tradition took the sight of a funeral procession as money arriving, and so regarded it especially well. If something has dragged on, it means the time has come for it to be settled.
Conducting a funeral for someone else
Something of yours is waiting to be closed off. Read it as a sign that it is time to hand on something you have been carrying, or to finish a greeting you have long deferred.
Wearing mourning clothes
Tradition read this as a dream of gaining office or standing, treating white robes as the dress of a formal occasion. Today, take it as a flow in which you formally take on some role.
Seeing the funeral of someone still living
It does not mean harm will come to them. It was read as a sign that your relationship with that person will change from what it is now, usually towards being settled a stage or begun afresh. A startling scene, but not an ill omen.
If you have lately buried someone close, count first how many days since then you have actually rested, before asking what the dream means. If the same scene keeps returning and it weighs on your days, help from a professional comes before interpretation.