1.The fourth letter of the English alphabet, and a vocal consonant. The English letter is from Latin, which is from Greek, which took it from Phoenician, the probable ultimate origin being Egyptian. It is related most nearly to t and th; as, Eng. deep, G. tief; Eng. daughter, G. tochter, Gr. qygathr, Skr. duhitr.
2.(Mus.) The nominal of the second tone in the model major scale (that in C), or of the fourth tone in the relative minor scale of C (that in A minor), or of the key tone in the relative minor of F.
3.As a numeral D stands for 500. in this use it is not the initial of any word, or even strictly a letter, but one half of the original Tuscan numeral for 1000.
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