ordinal number第一,首先
adverb第一,首先;第一次,首次;首先;起初,起先;第一,首先
noun第一个人(或事物)
ordinal numberbefore all the others
adverbbefore all the others
adverbbefore all the other times
adverbbefore doing or listing anything else
adverbat the beginning
adverbbefore anything else
nouna person or thing that comes earliest or before all others