|Easton's Bible Dictionary|
(1.) In Isaiah 58:5 the rendering of a word which denotes "belonging to a marsh," from the nature of the soil in which it grows (Isaiah 18:2). It was sometimes platted into ropes (Job 41:2; A.V., "hook, " R.V., "rope, " lit. "cord of rushes").
(2.) In Exodus 2:3, Isaiah 18:2 (R.V., "papyrus") this word is the translation of the Hebrew gome, which designates the plant as absorbing moisture. In Isaiah 35:7 and Job 8:11 it is rendered "rush." This was the Egyptian papyrus (papyrus Nilotica). It was anciently very abundant in Egypt. The Egyptians made garments and shoes and various utensils of it. It was used for the construction of the ark of Moses (Exodus 2:3, 5). The root portions of the stem were used for food. The inside bark was cut into strips, which were sewed together and dried in the sun, forming the papyrus used for writing. It is no longer found in Egypt, but grows luxuriantly in Palestine, in the marshes of the Huleh, and in the swamps at the north end of the Lake of Gennesaret. (see CANE.)
Noah Webster's Dictionary
(n.) A kind of large rush, such as the papyrus and the cattail, growing in wetlands or in water.
Int. Standard Bible Encyclopedia
Bulrush (3 Occurrences)
Isaiah 9:14 For this cause the Lord took away from Israel head and tail, high and low, in one day. (See NAS)
Isaiah 19:15 And in Egypt there will be no work for any man, head or tail, high or low, to do. (See NAS)
Isaiah 58:5 Is it such a fast that I have chosen? a day for a man to afflict his soul? is it to bow down his head as a bulrush, and to spread sackcloth and ashes under him? wilt thou call this a fast, and an acceptable day to the LORD? (KJV JPS DBY WBS)