Abarim Publications' online Biblical Hebrew Dictionary
The two forms רקק (rqq) and ירק (yrq) are so kindred that it's not always clear which one we're looking at. Officially each form covers two roots but it may very well be that these words are all the same and express to be small, young and insignificant (to be green, to be a greenhorn).
The verb רקק (raqaq I) occurs all over the Semitic spectrum. It means to be thin and figuratively to be weak or slender. In the Bible this root does not occur as verb but only as the following derivatives:
- The adjective רק (raq), meaning thin. It occurs only three times but only to describe the seven thin cows of Pharaoh's dream (Genesis 41:19, 41:20 and 41:27).
- The identical adverb רק (raq), which conveys restriction. It means only (Genesis 14:24, Deuteronomy 2:35, 1 Samuel 1:13) or solely (Genesis 6:5) or even surely (Genesis 20:11).
- The masculine noun רקיק (raqiq), denoting a thin cake or wafer of unleavened bread (Exodus 29:23, Numbers 6:19, 1 Chronicles 23:29).
- The feminine noun רקה (raqqa), denoting the temple, the sides of one's head (Judges 4:21, Song of Solomon 4:3).
The verb רקק (raqaq II) means to spit (Leviticus 15:8 only; describing the spitting of a man who also had a discharge). It appears to be related to the verb ירק (yaraq II), meaning the same (see below). Its sole derivative is the masculine noun רק (roq), meaning spittle, always as signs of contempt (Job 30:10, Isaiah 50:6). Note that in Hebrew symbolic jargon, learning and eating had a lot to do with each other. Since saliva provides the very first step in the physical digestion process, it's not unthinkable that spit was associated with the first (that is simplest) step in thought processing.
The root ירק (yaraq I) also occurs across the Semitic spectrum, always denoting a color ranging from green or pale to ashen or dusky-white or even silver. Note that in nature, smaller things are usually green (leafs, grasses), whereas bigger things are usually not (fruits, tree trunks). That would explain the connection with verb רקק (raqaq I), meaning to be thin.
- The masculine noun ירק (yereq) means green or green things (Genesis 1:30, Numbers 22:4, Isaiah 15:6).
- The masculine noun ירק (yaraq) means herbs or herbage (Deuteronomy 11:10, Proverbs 15:17, Isaiah 37:27).
- The masculine noun ירוק (yaroq) means green thing and occurs only once, in Job 39:8.
- The masculine noun ירקון (yeraqon), meaning either mildew (Deuteronomy 28:22, 1 Kings 8:37, Amos 4:9) or paleness (Jeremiah 30:6).
- The adjective ירקרק (yeraqrag) meaning greenish or pale-green. In Leviticus 13:49 it's used for sickly spots and in Psalm 68:14 the same word is used for glittering gold.
The verb ירק (yaraq II) means to spit. It occurs twice, in Numbers 12:14 and Deuteronomy 25:9, both as demonstrations of contempt, perhaps in the sense of to belittle (or in this case make thin). Some scholars contest that this verb is from a whole other root and place it among the green-words. It's also not unthinkable that showing contempt by means of spitting in someone's face went along with verbal abuse, wishing the recipient pale green eruptions on the skin.