Entry: pia meter (n.)
In context: "The Union's soft latex-polymer roof is cerebrally domed and a cloud pia mater pink except in spots where it's eroded down to pasty gray, and everywhere textured, the bulging rooftop, with sulci and bulbous convolutions."
Definition: The innermost of the three meninges, consisting of a thin, vascular, fibrous membrane which is closely applied to the surface of the brain and spinal cord.
Other: I'm fine if you just take Wallace's word for the colour of the pia meter. Really.
SNOOT score: 1
Source: Oxford English Dictionary