Heaven

Smith’s Bible Dictionary · William Smith, F. N. Peloubet, M. A. Peloubet

There are four Hebrew words thus rendered in the Old Testament which we may briefly notice.

Rakia , Authorized Version, firmament. [FIRMAMENT]
Shamayim . This is the word used in the expression "the heaven and the earth," or "the upper and lower regions." (Genesis 1:1)
Marom , used for heaven in (Psalms 18:16; Isaiah 24:18; Jeremiah 25:30). Properly speaking it means a mountain as in (Psalms 102:19; Ezekiel 17:23)
Shechakim , "expanses," with reference to the extent of heaven. (33:26; Job 35:5) St. Pauls expression "third heaven," (2 Corinthians 12:2) had led to much conjecture. Grotius said that the Jews divided the heaven into three parts, viz.,
The air or atmosphere, where clouds gather;
The firmament, in which the sun, moon and stars are fixed;
The upper heaven, the abode of God and his angels, the invisible realm of holiness and happiness the home of the children of God.

In other dictionaries

William Smith; revised by F. N. Peloubet and M. A. Peloubet; CrossWire SWORD module Smith 1.3

Bible Strong digital edition from CrossWire module 1.3, based on the 1884 Peloubet revision with later digital enrichments preserved