柯林斯詞典May Day 1. N-UNCOUNT May Day is the 1st of May, which in many countries is celebrated as a public holiday, especially as one in honour of working people. 五一國際勞動節(jié) 返回 May Day劍橋詞典the first day of May, a holiday in many countries . It traditionally celebrates spring but now it is often used to honour workers . 五一國際勞動節(jié)；五朔節(jié) 返回 May Day