DALETH. The fourth letter in the Heb. alphabet (ד), originally shaped like a triangle with no projecting leg at the right-hand corner (such as characterized the letter rēsh) until the 7th century b.c. and thereafter (when it became more easily confused with (ר), rēsh, even though the latter normally had a longer tail projecting from its lower right angle). Later on, when “square Heb.” characters developed (apparently in Aram. circles during the 6th cent.), daleth assumed the shape of an up-side-down “L” (with the short horizontal arm projecting leftward); oddly enough, rēsh also assumed a similar shape (ר), except that the angle corner was somewhat rounded, and never developed a tittle (or projection to the right of the vertical stroke) as daleth did. This letter was pronounced d as in Eng., although in later times it spirantized to the th sound in the Eng. “this” when it was preceded by a vowel sound. As a numerical sign, daleth represented the number four.
International Standard Bible Encyclopedia (1915)
The 4th letter of the Hebrew alphabet, and as such used in