Definitions:

1. The 4th letter of the alphabet. noun
   • In the alphabet, D is the fourth letter, coming after C and before E.
2. The fourth highest category of academic mark. NOUN
   • She was disappointed to receive a D on her math test, knowing she needed to study harder.
3. The Roman numeral for 500. adjective
   • The ancient manuscript was estimated to be written in the year D, indicating it was from the year 500 in the Roman numeral system.
4. The second note of the diatonic scale of C major. NOUN
   • The piece begins with a striking chord that includes a D major.

Synonyms:

• five hundred