Question: what does fancy dress mean in the uk
[{'answer': 'A costume', 'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 9, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'guests dress up in costumes', 'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'start_paragraph_id': 1, 'start_character': 149, 'end_paragraph_id': 1, 'end_character': 176, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'costumes', 'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'start_paragraph_id': 1, 'start_character': 168, 'end_paragraph_id': 1, 'end_character': 176, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'a type of party , common mainly in contemporary Western culture , where guests dress up in costumes'}, {'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 273, 'bleu_score': 0.953991849837532, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4602421731911688700}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4602421731911688700}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1348524', 'title': 'Costume party', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['guests dress up in costumes', 'A costume party (American English) or a fancy dress party (British English) is a type of party, common mainly in contemporary Western culture, where guests dress up in costumes. Costumed Halloween parties are popular in the United States, Canada, Australia, and New Zealand.', 'A costume party (American English) or a fancy dress party (British English) is a type of party, common mainly in contemporary Western culture, where guests dress up in costumes']}}]}]