This word has various meanings in the Bible.
used to denote the means by which a door is bolted (Neh. 3:3)
A bar for a door was of iron (Isaiah 45:2), brass (Psalms 107:16), or wood (Nahum 3:13).
a rock in the sea (Jonah 2:6)
the shore of the sea (Job 38:10)
strong fortifications and powerful impediments, etc. (Isaiah 45:2; Amos 1:5)
defenses of a city (1 Kings 4:13)