Abarim Publications' online Biblical Hebrew Dictionary
The root צדד (sdd) isn't used as a verb in the Bible, but in Arabic it means to turn away, shun or alienate. In the Old Testament remains only the derived masculine noun צד (sad), meaning side.
The noun צד (sad) may describe the physical side of a person (2 Samuel 2:16, Joshua 23:13) — from whence comes the enigmatic expression "thorn in one's side" (Numbers 33:55, Judges 2:3, and possibly 2 Corinthians 12:7 and even John 19:34) — or nearness to a person (being by the side of: Ruth 2:14, 1 Samuel 20:25, Psalm 91:7, 1 Samuel 20:20) or to some geographical location (a town: Joshua 3:16, 12:9; a mountain: 1 Samuel 23:25, 2 Samuel 13:34).
The side may be used to lay on (Ezekiel 4:4), to carry a child on (Isaiah 60:4 and 66:12), or to shove others out of the way with (what sheep do: Ezekiel 34:21).
Apart from mountains and towns, our noun צד (sad) is curiously enough almost only applied to lifeless things that have to do with the tabernacle: The tabernacle itself had sides (Exodus 26:13), as did the gold Menorah (Exodus 25:32), as did the altar of incense (Exodus 30:4), as did the Ark of the Covenant (Deuteronomy 31:26).
The only exception to this unexplained pattern is the Ark of Noah, which had a side in which Noah constructed a door (Genesis 6:16).