d noun
plural d's or ds or D's or Ds
plural d's or ds or D's or Ds
Learner's definition of D
1
: the fourth letter of the English alphabet英语字母表的第4个字母 [count]
[noncount]
2
: a musical note or key referred to by the letter D : the second tone of a C-major scale*D音(C大调音的第2音或音符);D调 [count]
[noncount]
3
[count] : a grade that is given to a student for doing poor work学业成绩)第四等,差等 4
: the Roman numeral that means 500(罗马数字)五百