<span>An omen is believed to be a sign which foretells the future; however, an omen usually has no scientifc background is produced purely from the intuition of individual. Antynoms of omen may include "past" or "after effect" as these words discuss smaller events after a significant event.</span>
Regional Dialect is the answer
The capitalization may be to further convey the personification that the speaker is using in this poem, making the Moon a person that they are "pleading with"