thirteenth
ordinal number uk/θɜːˈtiːnθ/ us/θɝːˈtiːnθ/
第十三
13th written as a word
My birthday is on the thirteenth (of October). 我的生日是（10月）13日。
thirteenth
noun [ C ] uk/θɜːˈtiːnθ/ us/θɝːˈtiːnθ/
十三分之一
one of thirteen equal parts of something