Abarim Publications' online Biblical Hebrew Dictionary
There are two distinct but identical roots ערף ('rp) in Biblical Hebrew, and they appear to have nothing in common:
The root ערף ('rp I) isn't used in the Bible and we have no idea what it might have meant. But it yields a derivation which occurs thirty-three times: the masculine noun ערף ('orep), meaning neck. The noun hardly if ever shows up as mere reference to the body-part, and mostly in figurative senses: to have one's dominant hand on someone's submissive neck (Genesis 49:8), to turn one's neck to someone in fear (Exodus 23:27), and being stiff-necked in arrogance and rebellion (Exodus 32:9, Jeremiah 7:26).
A secondary derivation is a denominative verb created from the noun: ערף ('arap), literally meaning to neck, which in practice comes down to breaking the neck of an animal (Exodus 13:13, Isaiah 66:3).
The root ערף ('arap II) means to drip or drop. This verb occurs a mere two times in the Bible, in Deuteronomy 32:2 and 33:28. This verb yields two derivatives:
- The masculine noun עריף ('arip, meaning cloud (Isaiah 5:30 only).
- The masculine noun ערפל ('arapel), denoting a heavy dark cloud-mass (Exodus 20:18, 1 Kings 8:12, Psalm 97:2). It's unknown how or why the letter ל (lamed) was post-fixed to the root to create this noun.