What does a marriage line starting from the back of the palm mean?

What this means

First confirm that the mark starts from the outer edge below the little finger and then runs into the palm.

Traditional palmistry reads a clear, unbroken line from the edge as a stronger attachment sign, but not as proof of legal marriage.

If the line is broken, cut, islanded or curves downward, the relationship meaning becomes more complicated and should be read with the whole palm.