ममसत्य is the Sanskrit word for a being mine. There are three uses of this word that we are interested in. One is male, one is female, one is both.
One, the accepted version, is that it means a 'contest of ownership' although it employs a spurious grammatical anomaly, it should be ahamsatya if it means that.
In it's prima facie form, mamasatya is a place where you would 'mine' for 'beings' as one might mine for gems. This association with mining suggests that there may have been elves at work, way back in the Vedics. Inner visions, either stress-induced, or plant-induced, or both.
The final and rather obvious possibility is that the beings are babies and 'the being mine' is the place from which babies emerge.
We will instruct the spider elves to run a context check on all instances in the literature. Damn cat! Nearly scared the life out of me! Be good.