"Nonplussed" = bewildered, perplexed, at a loss for what to say or do; "unfazed" = unaffected, calm and composed despite difficulty.
Adjective: bewildered, perplexed, completely at a loss for how to react to something unexpected or surprising. "She was nonplussed by his reaction" = she was left bewildered by his reaction (she did not know how to respond). From Latin "non plus" = no more (there is nothing more one can do or say). VERY COMMON ERROR in modern American English: many people use it as if it meant "unimpressed" or "unfazed", which is the exact opposite.
When the journalist asked about the scandal, the minister appeared nonplussed — he paused, looked away, and struggled to form a coherent response.
The student was nonplussed by the exam question — it covered material that had never appeared in any of the practice tests.
He was nonplussed by her sudden announcement that she was quitting the company to travel the world.
Adjective: not affected, disturbed, or unsettled by something difficult, shocking, or troubling. "She was unfazed by the criticism" = she was not rattled by the criticism. Positive connotation: serenity, composure, imperturbability. It is the exact OPPOSITE of what "nonplussed" actually means.
Despite the hostile reception, the speaker remained completely unfazed — she continued her presentation without a pause.
He was unfazed by the complexity of the problem — after years in the industry, he had seen worse.
The veteran officer remained unfazed by the chaos around her, calmly directing the evacuation.
Common mistake
The most surprising modern error: in colloquial American English, "nonplussed" has started to be used as a synonym for "unfazed" (unimpressed, indifferent, unmoved). Many people write "he was nonplussed by the news" meaning "he was not rattled by the news" — but the real, traditional meaning is the exact OPPOSITE: "he was completely bewildered and at a loss by the news". This confusion is so common that some modern dictionaries already recognize the American informal meaning as a secondary variant, which infuriates language purists.
Trick to remember it
NON-PLUSSED: "non plus" in Latin means "no more" — as in, you cannot add anything more, you are stuck. When something nonplusses you, you have NOTHING MORE to say or do — you are BEWILDERED. Think: nonplussed = NO PLUS = cannot proceed = perplexed. UNFAZED: "faze" means to disturb or disconcert — so "un-fazed" = NOT disturbed. NONPLUSSED and UNFAZED are exact opposites. Nonplussed person: wide eyes, open mouth, stuck. Unfazed person: calm face, no reaction, carries on.
Quick rule
Nonplussed = bewildered, perplexed, at a total loss for how to react (traditional and correct). Unfazed = unaffected, calm and composed, not disturbed.
Did you know?
The confusion between "nonplussed" and "unfazed" is so widespread in American English that linguist Arnold Zwicky identified it as a "semantic flip": when the meaning of a word gradually inverts in popular speech until many educated speakers use the word with the opposite meaning from the original. Other examples of the same phenomenon: "terrific" (originally = causing terror; now = excellent) and "awful" (originally = inspiring awe; now = horrible). The prescriptivist question is: when the incorrect usage outnumbers the correct one in frequency, does it cease to be an error?
Exercise 1 · Pick the right one
When the auditors revealed a seven-figure discrepancy in the accounts, the CFO appeared completely _____, staring at the report and unable to speak for nearly a minute.
Exercise 2 · Pick the right one
Despite receiving harsh criticism from three senior partners, she remained completely _____, calmly presenting her next point as though nothing had been said.
Exercise 3 · Form the word
Nonplussed = bewildered, perplexed, at a total loss for how to react (traditional and correct). Unfazed = unaffected, calm and composed, not disturbed.
The most surprising modern error: in colloquial American English, "nonplussed" has started to be used as a synonym for "unfazed" (unimpressed, indifferent, unmoved). Many people write "he was nonplussed by the news" meaning "he was not rattled by the news" — but the real, traditional meaning is the exact OPPOSITE: "he was completely bewildered and at a loss by the news". This confusion is so common that some modern dictionaries already recognize the American informal meaning as a secondary variant, which infuriates language purists.
NON-PLUSSED: "non plus" in Latin means "no more" — as in, you cannot add anything more, you are stuck. When something nonplusses you, you have NOTHING MORE to say or do — you are BEWILDERED. Think: nonplussed = NO PLUS = cannot proceed = perplexed. UNFAZED: "faze" means to disturb or disconcert — so "un-fazed" = NOT disturbed. NONPLUSSED and UNFAZED are exact opposites. Nonplussed person: wide eyes, open mouth, stuck. Unfazed person: calm face, no reaction, carries on.
Bryan López
Founder of SpeakUP Academy