Grove

Boyd’s Bible Dictionary:

Except
(Gen. 21:33), the Hebrew original means an idol; primitively set up and worshipped in groves (1 Kings 18:19; 2 Kings 13:6).

Concise Bible Dictionary:

1. eshel, a tamarisk, or perhaps any large tree. Abraham planted a memorial tree in Beer-sheba, and called there on the name of Jehovah (Gen. 21:33). The same word is translated “tree” in the AV in 1 Samuel 22:6 (“grove” in margin) and 1 Samuel 31:13.
2. asherah, asherath. The word “grove” naturally suggests a row of trees, but that this cannot be the meaning is evident from groves being set up “under every green tree” (1 Kings 14:23; 2 Kings 17:10). Manasseh set a graven image of the grove that he had made in the temple, which Josiah removed, burnt, and ground to powder (2 Kings 21:7; 2 Kings 23:6). This was doubtless made of metal, but the groves were of wood, as we learn from their being cut down, and burnt ({vi 6680-6681}Judg. 6:25-26; {vi 10180-10181}2 Kings 23:14-15). One passage speaks of groves being planted (Deut. 16:21); another, of their being made, and another, of their being built ({vi 9234;9242}1 Kings 14:15, 23). They are constantly associated with idols and images, and Judges 3:7 speaks of their being served along with Baalim.
On the whole it seems most probable that they were wooden symbols of a goddess, in the form of images or pillars, or mere stems of trees inserted in the earth. In 2 Kings 23:7 we read that women wove “hangings” for the groves, but these were literally “houses” or “tents,” which implies that they enclosed the groves, probably for impure purposes, for immorality was almost constantly associated with idolatry. Kalisch and others suppose that the name Asherah has reference to the Syrian goddess Astarte, and it is so translated by the LXX in 2 Chronicles 15:16. Fürst refers it to the Phoenician nature-god. The many references to the idols, images, and groves show how far Israel had departed from the living God and fallen into idolatry.