The Hekhal was the largest part of the Temple of Solomon. It contained the menorah and the table of shewbread.
The word "hekhal" is a loanword; a borrowing of the Akkadian ekallu, meaning "palace". The Akkadians, in turn, got the word from the Sumerian e-gal, meaning "big/great house". Hekhal was already a well established borrowing by the 10th century BC. While the word referred particularly to the nave of the temple, it could also be used to refer to the temple itself. The meaning of this word suggests the Hekhal as having been a possible source for Nephi's and Lehi's description of a "great and spacious building" in their respective visions of the Tree of Life and Iron Rod.
Analogy with Hebrew roots connects the Hekhal with the ideas, "everything", and "easing", via the Hebrew terms "ha-kol", and "hekel", respectively.
A closely related akkadian word arad-ekalli, "meaning palace worker", was borrowed into Hebrew as "adrichal", meaning "architect".
The Hekhal would be entered from the Ulam, and would provide entry to the Debir