These two words look like twins, and they are. But today they do very different jobs: one is about clothes, and the other is about habits and traditions.
- Costume is what you wear to look like someone or something else.
- Custom is something that a person or a group usually does.
Costume: the outfit
A costume is a set of clothes that makes you look like a character, an animal or a person from another time. You wear it for a play, a party, a parade or a carnival.
Maya wore a dragon costume to the school play.
The theatre keeps hundreds of old costumes in a big wardrobe.
Dad made my robot costume out of three cardboard boxes.
You will often see it in the phrase costume party, and you can also use it for the clothes people wore in a past period: a costume from the 1800s.
Custom: the habit or tradition
A custom is something that people in a family, a school, a town or a country usually do, and that has become a tradition.
It is a custom in our family to eat pancakes on Sunday.
Taking off your shoes at the door is a custom in many homes.
The school has a custom of ringing a bell on the first day.
It can also be an adjective that means made specially for one person: custom shoes are made to fit one pair of feet.
Easy way to tell them apart
Ask: am I talking about clothes, or about what people do?
- Clothes you put on for a role: costume.
- A habit or tradition: custom.
💡 The OddLingo Trick
Look at the vowels.
Costume has an O, as in outfit. Custom has a U, as in us: it is something us people do.
🕵️ Where did they come from?
They are not just twins by luck. Word historians call a pair like this doublets: two words that started as one. Both words started as one Latin word, consuetudo, which meant a habit or usual way of doing things.
- Custom came into English around the year 1200, through Old French.
- Costume came much later, in 1715, through Italian and then French.
When costume first arrived, it was a word for artists. It described the clothes that suited the customs of a time and place, so a painting of an old scene showed the right outfits. Over time, the word shrank to mean just the clothes.
So a costume is really the custom of dress from a certain time. The spelling split because the two words took different roads.
⚠️ Common mistakes
Do not wear a custom.
❌ I wore a witch custom to the party.
✅ I wore a witch costume to the party.
Do not follow a costume.
❌ It is a costume in my family to sing before dinner.
✅ It is a custom in my family to sing before dinner.
Say them differently.
❌ COS-tum for the outfit
✅ COS-tyoom (the outfit) and CUS-tum (the habit)
📌 Good to know
- Customs with an S can mean the place at an airport or a border where officials check what people carry. We went through customs. It is a different meaning of the same family.
- Custom-made means made specially for one person: a custom-made guitar.
- A custom is not always old: a family can start a new custom this year.
💬 In a conversation
Sam: Is the pumpkin outfit a costume or a custom?
Mia: It is a costume. A custom is something you do, not something you wear.
Sam: So wearing it every year is a custom?
Mia: Yes. The costume is the pumpkin, and the custom is the wearing.
Sam: And the custom of eating the sweets afterwards?
Mia: Very important custom.