In continuation of the post costumbre, let’s look at the word costume.
What Spanish word you use for costume really depends on what kind you mean.
One type of costume is traje, this would be a suit or outfit for a specific purpose. Such as, a traje de baño is a bathing suit. A traje de ceremonia is formal attire. A traje de chaqueta is a woman’s suit.
Another type of costume would be disfraz. This would be a disguise or to dress up as someone or something else. The kind the kids wear to costume parties.

In Spain, we also say ‘Ropa de vestir’ meaning good clothes (usually quality clothes) which we use for special occasions, we use ‘traje’ without more qualifications when we mean a bussines suit (for a man usually, for a woman we use ‘traje de chaqueta’)
[...] I am not talking about the verb, rather the noun. A traje de smoking, or commonly just called smoking, is a tuxedo. When we were in language school it took [...]