The absinthma, 2560/2541, is the difference between 80/77 and 33/32. When tempered out, it splits 15/14 into two equal parts of those sizes. It is also the sum of 243/242 and 5120/5103.
It is a valuable 11-limit comma, as tempering it out causes 16/11 to be exactly halfway between 7/5 and 3/2.
This comma is tempered out in both magic and thuja, and so is named the absinthma. Thujone is often believed to be a component of absinthe, and its supposed effects, as well as the bohemian lifestyles associated with absinthe, give an association with magic.