costume B1

/ˈkɑsˌt(j)um/ A set of clothes worn to look like someone or something else, often for fun. M S

custom A2

/ˈkʌstəm/ A traditional way of behaving or doing something that is common to a group or society. M S

customarily C2+

/ˌkʌstəˈmɛrəli/ according to usual practice; ordinarily M S

consuetude C2+

/ˈkɑnswəˌtuːd/ an established custom or usage, especially with legal force M S

unaccustomed C2+

/ˌʌnəˈkʌstəmd/ not used to something; unfamiliar or unusual M S