My brother's definitions are funnier, but...
fris·son ( P ) Pronunciation Key (fr-s)
n. pl. fris·sons (-sz, -s)
A moment of intense excitement; a shudder: The story's ending arouses a frisson of terror.
The context: from the Christian Science Monitor:
February 23, 2004 edition
New wild card: Nader joins race
The consumer advocate announced his candidacy Sunday, on the heels of Dean's withdrawal. Democrats are chagrined.
By Linda Feldmann | Staff writer of The Christian Science Monitor
WASHINGTON – Ralph Nader has sent a frisson of anxiety through the Democratic Party by announcing he will run for president.
Ralph Nanny's gonna save us all.
Update: I got the definition from Dictionary.com.