The Anti-Rameumptom

In this article, Matthew Bowen makes a compelling case for a meaning of the name "Onidah" in the Book of Mormon.

We encounter the Hill Onidah in Alma 32:4 as the setting for Alma-2's sermon about faith.

Bowen sets the Hebrew meaning for Onidah as:

ʿŏnî /ʿōnî/ʿônî (ʿonyî, “my affliction”) + yādaʿ/yēdaʿ (“he knew,” “he knows”) — i.e., “he has acknowledged my affliction” or “he knows my affliction.”

Once again, Mormon displays a keen ability to add deeper layers of meaning into his narrative through the use of names. Consider the context:

1. This place name comes right after a description of the Rameumptom in Alma 31:12-23.
2. The Rameumptom was a high place where the wealthy gathered once a week to manifest their pride.
3. The name "Rameumptom" seems to contain the Hebrew root for "pride, haughtiness, arrogance."*
4. Alma's heart is grieved at the display of pride, and seeing that their hearts were set upon riches. (Alma 31:24).
5. Alma prays for strength: "...wilt thou comfort my soul in Christ. O Lord, wilt thou grant unto me that I may have strength, that I may suffer with patience these afflictions which shall come upon me, because of the iniquity of this people." (Alma 31:31)
6. Alma prays for the success and comfort of his missionary companions: "...Wilt thou grant unto them that they may have strength, that they may bear their afflictions which shall come upon them because of the iniquities of this people." (Alma 31:33) 
7. They are blessed: "And the Lord provided for them that they should hunger not, neither should they thirst; yea, and he also gave them strength, that they should suffer no manner of afflictions, save it were swallowed up in the joy of Christ. Now this was according to the prayer of Alma; and this because he prayed in faith." Alma 31:38)
8. Two verses later we learn that the missionaries "began to have success among the poor class of people;" (Alma 32:2) who had been cast out of the synagogues because of their poverty. "...being esteemed as filthiness; therefore they were poor; yea, they were esteemed by their brethren as dross**; therefore they were poor as to things of the world; and also they were poor in heart." (Alma 32:3)
9. Alma encounters these cast-off poor people as they approach him on the Hill Onidah, where he is teaching.  They come to him (interesting detail) in answer to his prayer: "O Lord, wilt thou grant unto us that we may have success in bringing them again unto thee in Christ. Behold, O Lord, their souls are precious, and many of them are our brethren; therefore, give unto us, O Lord, power and wisdom that we may bring these, our brethren, again unto thee." (Alma 31:34-35)
10. Alma proceeds to teach them that poverty is a blessing when it leads to humility and a willingness to be taught:

8 I behold that ye are lowly in heart; and if so, blessed are ye. ...
12 I say unto you, it is well that ye are cast out of your synagogues, that ye may be humble, and that ye may learn wisdom; for it is necessary that ye should learn wisdom; for it is because that ye are cast out, that ye are despised of your brethren because of your exceeding poverty, that ye are brought to a lowliness of heart; for ye are necessarily brought to be humble.
13 And now, because ye are compelled to be humble blessed are ye; for a man sometimes, if he is compelled to be humble, seeketh repentance; and now surely, whosoever repenteth shall find mercy; and he that findeth mercy and endureth to the end the same shall be saved.

Thus, on the hill which bears the name "He knows my affliction," Alma's prayer is answered and his affliction (a heart that is grieved by the pride of the people) is acknowledged by God.

The Hill Onidah is set up as the perfect "Anti-Rameumptom," a high place of a different type, where the word of God is taught to the poor in heart after they are cast out of the synagogue and considered as "dross" by those whose hearts are set upon gold and riches.

A summary of contrasting themes:

Rameumptom--

1. high place where the prideful gather to show off, 
2. hearts set upon riches, 
3. "puffed up" in pride 
4. reject Christ
5. the poor are esteemed as dross by the prideful/wealthy

Onidah--

1. high place where the humble/poor seek the word, 
2. "poor in heart"
3. "truly penitent"
4. prepared to hear the word
5. the poor are esteemed as "precious" by the missionaries

* See this explanation from Bowen's paper:

The pejorative connotations of Semitic/Hebrew rām (*rwm) in terms of “high,” “haughty,” “arrogant,”21 “proud” not only find expression in the “height” of the Rameumptom (described as “high above the head,” Alma 31:13) and their “lifted up” hearts,22 but also in the ostentatious display of one’s clothing demanded by the worshipper’s “standing on the top [of the Rameumptom] and stretch[ing] forth [one’s] hands towards heaven and cry[ing] with a loud voice” in such a public way. The “costly apparel, and their ringlets, and their bracelets, and their ornaments of gold, and all their precious things” would have become, in effect, the garb expected of the worshipper, functioning as quasi-sacred or religious clothing.

** "Dross" is waste removed from a metal, such as in the process of  refining gold.