Below is the definition from Merriam Webster.
I kind of really like choice no. 4.
I like the “final state of matter falling into a black hole”
When singular, as so many of us 50 somethings are, it often feels as if we are existing (or non existing) in a black hole.
: something that is singular: such as
a : a separate unit
b : unusual or distinctive manner or behavior : peculiarity
2: the quality or state of being singular
3: a point at which the derivative of a given function of a complex variable does not exist but every neighborhood of which contains points for which the derivative does exist
4: a point or region of infinite mass density at which space and time are infinitely distorted by gravitational forces and which is held to be the final state of matter falling into a black hole