Often misused as meaning unfazed, but actually means bewildered.
English majors are nonplussed about how "nonplussed" has, over time, become so misused.
by ekf March 28, 2005
(Verb) Unable to act, speak, or think; bewilderd
After reading many letters and statements, Gean was nonplussed by it all and had to take a breath.
by binomialNomenclaturesk November 24, 2009
When someone is lickin' on a D
I'm completely nonplussed.
by treasureman July 19, 2011
When your bank card won't work at another bank's ATM because your bank is on the Plus System debit network, but the ATM is not.
Many "foreign ATMs" are on the Interlink or Star networks -- they are nonplussed.
by FuzzyBS March 4, 2011
Bemused. This is the adjective derived from the verb nonplus.

Oxford Dictionary:
nonplussed: (of a person) surprised and confused so much that they are unsure how to react.

Part of speech: adj.
The battle was so bemusing and preliminary that they were nonplussed.
by SpeedoThreeSixty December 27, 2021
Someone that doesn't have a Google+ Account, or perhaps any other social network account. A person who may have no knowledge of social networks.
You missed the party? I had no idea you were Nonplussed.
by Kingmikey July 15, 2011