Elul

The Hebrew month of Elul אֱלוּל begins this week, so let's look at its etymology. As with the other names of the months in the current Hebrew calendar, it was adopted in Babylonia, and therefore has Akkadian origin. Klein writes that it derives from an Akkadian word reflecting its function as the beginning of the harvest period:

Akka. ulūlu, elūlu (= harvest, harvest time; lit.: ‘the time when the produce of the land is brought in’). Related to Aram. עֲלַל (= he brought in), Aram.-Syr. אֲלַלְתָּא (= that which is brought in, produce, harvest), Heb. עֹל (= yoke), Akka. allu, ullu (= yoke, chain), Arab. ahalla (= he put in, thrust in), ghall (= iron ring round a prisoner’s neck at which his hands are tied.

This etymology connects Elul to the root עלל, which is also the origin of ol עֹל - "yoke." However, עלל provides two roots, which Klein (and others) claim as unrelated.

We've been discussing the second meaning (according to Klein) of עלל, which he defines as "to insert, thrust in." This meaning is actually unused in Biblical Hebrew, but it does appear in the Aramaic sections of the book of Daniel. (Kaddari also suggests that the appearance in Iyov 16:15 has the same meaning, and was influenced by Aramaic.)

The other (first) meaning of עלל does appear in Biblical Hebrew. Klein defines it as "to act, do, work" and notes that it is related to the Arabic ‘alla, meaning "to do something a second time." While at times עלל can have the neutral meaning of "to act," in some instances it can mean to act severely or harmfully. 

Here are some of the words deriving from this meaning of עלל:

• עָלוּל alul - "liable, likely, capable (of doing an action)." In 1944, the linguist Yitzchak Avinery (Yad HaLashon, p. 450) lamented that people are using alul in a positive sense, and not just the negative sense it should have. He wrote that the positive equivalent is asui עָשׂוּי. According to Morfix, today alul still has a negative connotation, and is used when something bad is likely to happen. But perhaps it's used more broadly, even in positive scenarios, because asui has another meaning - "made of."
• עֲלִילָה alila - This word has two meanings, the more neutral "act, deed" (now also "plot, story") and the more negative "false accusation, libel."
• עִלָּה ila - "cause, reason." 
• הִתְעַלֵּל hitalel - "to act cruelly, to abuse."

Klein also adds olela עוֹלֵלָה - "gleaning (of grapes or olives)" but doesn't explain the connection. BDB, however, does provide an explanation, connecting it back to the Arabic root that Klein cited. They define gleaning as "going over a second time."

The similar word עוֹלָל olal, meaning "infant," does not derive from עלל, but rather from the root עול - "to suck, nurse."

I should note that Gesenius connects all of the terms we discussed. The nursing baby "drinks again", and the "thrusts" we saw in the second meaning of עלל (the one connected with Elul), are a "second blow." However, since the scholarship of Gesenius is older than the other sources I looked at, I don't know if it's still considered accurate.