What is the meaning of alef lamed dalet in Hebrew?

Answer 1

This is a bit oversimplified:

Aleph, Lamed and Dalet (אלד) are three letters from the Hebrew alphabet. In the order given, (Aleph Lamed Dalet) they comprise one of the seventy-two names of God which are unspeakable. As such, it might be more accurate to say they are the initials of one of the seventy-two names of god. Kabbalistic tradition variably has it that the name of God is either unspeakable because of it's otherworldly complexity or because God has forbidden it.

This is very similar to the term "Yahweh", often taken as a name for God but which is actually the Tetragrammaton: the name of four letters. Yahweh derives from a simplified pronunciation of the English transliteration (YHWH) of the four Hebrew letters Yodh He Waw and He. In German, the transliteration is JHVH which is often pronounced as Jehovah.

Each of the traditional (Kabbalist) 72 names of God are rendered thus, combining (usually three) letters from the Hebrew alphabet, and each of these names for God are said to be an especially potent protection from a specific type of harm or malefaction.

Now, according to Kabbalah (as in other mystical traditions) if you are harboring ill will towards me and you glare at me in passing, this can project your negativity towards me, thus preventing me from achieving my full potential - possibly even doing active harm. This is called "Ayin Horeh" and it (along with all such negative glances and envious looks) is the origin of the "evil eye" concept and the phrase "looks can kill".

The remedy and protection against this (according to Kabbalah) are a length of red wool string tied around the left wrist accompanied by a charm (usually in the form of a pendant or bracelet) on which is inscribed the name of God in the form of the three Hebrew letters Aleph, Lamed and Dalet. As to the red string, tradition has it that Rachel the Matriarch's greatest desire and purpose in life was to protect and defend all of her children from evil and so now she represents protection in the physical realm. A length of red string taken to her tomb in Israel and there imbued with her essence according to the proper rituals is believed to connect her to mortals who wear it on the left wrist (the left side of the body is the receptive side) and thus imparts her protection to them.

Answer 2

The word אלד means "I will give birth".