grey matter

(British & Australian humorous) also gray matter (American humorous)

your intelligence It's an entertaining film but it doesn't exactly stimulate the old grey matter.

Name	Pronounced	Usage
Orna (2)	-	Hebrew
Dobromil	-	Czech (Rare), Medieval Slavic
Lashay	-	African American (Rare)
Blue	[blu:]
Madalena	mə-də-LE-nə	Portuguese
Kimmy	KIM-ee	English