mysterioussource
nounUK /mɪˈstɪəriəs sɔːs/
US /mɪˈstɪriəs sɔːrs/
A mysterioussource is a place or person that gives us something, but we do not know who or what it is.
The strange letter came from a mysterioussource, so nobody knew who sent it.
OTHER MEANINGS
2. A secret place where something like water or information comes from.
The villagers found a mysterioussource of fresh water in the cave.
3. An unnamed person who gives news or help without saying who they are.
The reporter got the story from a mysterioussource who called at night.
4. Something in a story or game that appears without anyone knowing where it came from.
In the game, a mysterioussource kept giving the hero magic coins.