Nutcase
noun
Definition
1. (noun) A person who behaves in a crazy, strange, or extremely silly way — used informally and usually in a humorous or affectionate tone.
Context Alive
Your flatmate decided to go swimming in the sea in the middle of January. The water was freezing and everyone on the beach was staring at him like he'd lost his mind. He came running out after two minutes, shaking and laughing at the same time. You handed him a towel and called him an absolute nutcase. He just grinned and said he'd do it again next weekend.
Meanings
1 meanings 1 A Crazy or Wildly Silly Person (Noun) Common ▼
This meaning is about someone who acts in a wild, strange, or reckless way — but usually in a way that's funny rather than scary. Imagine your friend who signs up for a marathon with zero training, eats a full pizza the night before, and still shows up at the start line in fancy dress — you'd call him a complete nutcase. This is describing someone whose behaviour is so far from normal that you can't help but laugh or shake your head. You might say "my brother is a total nutcase — he just quit his job to travel the world with no savings", or someone could call their colleague a nutcase for cycling to work in a thunderstorm. Or think about that one friend in every group who always does the most ridiculous things at parties — dancing on tables, making weird bets, volunteering for everything — everyone agrees he's a lovable nutcase. The word suggests the person is harmlessly crazy and usually entertaining.
✏️ Nutcase is almost always used in a joking, affectionate way between friends. Calling a stranger a nutcase could sound rude, but calling your best mate one is a compliment. Be careful with context — in older or more formal usage, it could refer to someone with a mental health condition, which is now considered offensive. In modern casual English, it's lighthearted and playful.
Common Patterns
Basic Structures
a / an + (adjective) + nutcase → the standard pattern — often with an intensifier like complete, total, absolute
He jumped off the bridge into the river — the man is an absolute nutcase.
call someone a nutcase → to describe someone as crazy in a playful or exasperated way
She called me a nutcase for wanting to drive eight hours just for a burger.
Common Structures
a complete / total / absolute nutcase → adding emphasis to how crazy the person is — very common in spoken English
My neighbour is a complete nutcase — he mows his lawn at 6 a.m. on Sundays.
some nutcase → used when talking about an unknown person doing something wild
Some nutcase was running down the motorway in a dinosaur costume.
a bit of a nutcase → softer version — mildly eccentric rather than completely crazy
She's a bit of a nutcase, but everyone loves her energy.
Collocations
10 collocationscomplete nutcase
someone who is absolutely crazy in a funny or shocking way
total nutcase
fully and unquestionably eccentric or wild
absolute nutcase
emphasises just how crazy someone's behaviour is
a bit of a nutcase
mildly eccentric — crazy but in a charming, harmless way
lovable nutcase
someone who's crazy but everyone likes them for it
call someone a nutcase
to label someone as crazy, usually jokingly
some nutcase
an unknown person doing something wild or bizarre
certified nutcase
humorous exaggeration — as if their craziness is officially confirmed
look like a nutcase
to appear crazy because of what you're doing or wearing
act like a nutcase
to behave in a wild or irrational way
Example Sentences
10 examples
1
He's a complete nutcase — he just booked a skydiving trip for his 80th birthday.
He's totally crazy — he just signed up for a skydiving experience to celebrate turning 80.
2
Some nutcase was riding a shopping trolley down the hill in the middle of the night.
Some crazy person was rolling down the hill in a shopping cart at midnight.
3
My sister is a bit of a nutcase, but that's exactly why everyone loves being around her.
My sister is a little eccentric, but that's the reason everyone enjoys her company.
4
You'd have to be a nutcase to go camping in this weather.
Only someone out of their mind would go camping in conditions like these.
5
She called him an absolute nutcase for eating three whole pizzas in one sitting.
She said he was completely mad for finishing three entire pizzas at once.
6
The kids at school think their PE teacher is a nutcase because he makes them run in the rain.
The students think their sports teacher is crazy because he sends them running even when it's pouring.
7
I looked like a nutcase chasing my dog through the park in my pyjamas.
I must have seemed crazy running after my dog through the park wearing my sleepwear.
8
He's the kind of nutcase who would drive four hours just to try a new burger place.
He's the type of person mad enough to travel four hours just to eat at a new burger restaurant.
9
Everyone at the office thinks she's a lovable nutcase because of her wild ideas.
All her colleagues see her as a charming eccentric because she always comes up with outrageous suggestions.
10
Don't be a nutcase — you can't wear shorts to a job interview.
Don't be ridiculous — wearing shorts to a job interview is not acceptable.
Synonyms & Antonyms
6 items
Synonymsmaniac
can sound more intense or dramatic — sometimes used seriously, sometimes humorously
weirdo
focuses more on being strange than being wild — can sound slightly meaner
lunatic
stronger and more dramatic — can be playful but also genuinely critical
Antonymsbore
a dull, predictable person — the opposite of someone wild and entertaining
conformist
someone who follows rules and norms — never does anything unexpected
killjoy
someone who ruins fun — the opposite energy of a nutcase