b) the government department that checks goods coming into a country and collects any taxes on them:
the US customs service
4 [uncountable]formalBBTthe practice of regularly using a particular shop or business:
an advertisement to attract more custom
Smaller shops lose a lot of custom when supermarkets open nearby.
WORD CHOICE: WORD CHOICE: habit, custom, tradition, practiceA habit is something that you do often, because you have done it many times before.Do not use habit when you are talking about actions or ways of doing things that have existed among a group of people for a very long time. Use tradition or custom. Use tradition when the thing you are referring to has existed for many years, especially when it has been passed down from parents to children• It is a tradition in his family for all first-born males to be called Peter.Use custom to refer to something that is considered normal or polite, especially when you are talking about other countries or other times• the Japanese custom of taking off your shoes when you enter someone's houseUse practice to talk about the usual way of doing something in a particular area of life• the practice of killing animals for their fur ➔ See alsohabit
Definition from the Longman Dictionary of Contemporary English Advanced Learner's Dictionary.