Tinker's dam

What I learned from my daddy, almost seventy years ago, was that a "tinker's dam" was a small piecd of clay to hold the solder on a pan until the solder cooled and set.
You would not make a dam out of solder. It is what you melt to mend or tie something together either mechanically or to make a good electrical connection.

At least you did not write that it was the "profane language" of the lowly tinker. Heck, he had to be a craftsman to do his work.
Thanks for the link.

That sounds like a good explanation to me.