The Hebrew word Elohim is an expression used to name anything related to the subject of deity or divinity, and most notably it is the ancient name for God within Judaism. The word itself Elohim is of Northwest Semitic origin, and has been used to name God for thousands of years. Like the Hebrew word Seraphim, Cherubim, or Ophanim, Elohim is morphologically plural in nature, so it actual means gods, angels, or anything divine that is more than one. The singular term for the word Elohim is Eloah, a word that only appears in late Hebrew poetry and religious scripture, and is an imitation of it's Aramaic use. To add some confusion to the word itself, it appears in the Torah as Elohim, yet clearly as a singular noun within Hebrew grammar, and not as Eloah. In other cases within the Torah, the same word Elohim is clearly used in a plural form. So clearly it will take some knowledge of Hebrew grammar and Biblical context to separate the two.
The concept and idea of divinity went through fairly drastic changes throughout the early formation of the Israelite identity. The ambiguity of the word Elohim is the direct result of these changes set upon Hebrew grammar, which can only be described as an example of vertical translatability. Some scholars have concluded that it is conceivable that Elohim may have been rooted in ancient polytheistic ideas, well before the rock solid idea of monotheism emerged within the Rabbinical Judaism, and it remained unchanged through the transition. The ancient Hebrews had much contact with other polytheistic religions within Egypt and Babylon, and it wasn't until they finally emerged from captivity that the word Elohim shifted towards a more singular use. So one doesn't have to conclude that the ancient Israelites were polytheistic in any way due to this word change, however their language was influenced by polytheistic cultures and ideas.
With regard to the word Elohim in an English Christian context, it is used again as both singular and plural, instead of using both formats Eloah and Elohim. For example sometimes it will quite clearly refer to pagan gods, and then other times refer to the God of Israel. So it would seem that early Christian scholars simply opted to use the Jewish or Torah system for the word, instead of putting the singular form Eloah to use. It is interesting however to note that the Christian Bible uses the term Elohim only when referring to the singular God of the Israelites, whereas they avoid the word when referring to the father of Jesus Christ, and instead use the clearly singular word Jehovah. Why this is done is that clearly the ancient Christian scholars wanted to stay loyal to the much older Hebrew scriptures, while still being able to sharpen the singular verses plural distinction in New Testament word, sort of a best of both worlds idea.
In other Christian denominations such as Mormons or the Latter Day Saints, they use the term Elohim to describe God the Father, and then only use the word Jehovah for Jesus Christ. So clearly in this case the singular view of Elohim is without question, and part of a new paradigm to distinguish two sides of the same God, those being Jesus Christ and the Father. It's quite interesting to pluck ancient Hebrew words like this out of the Bible, and then examine them individually. In most cases you quickly realize that each Hebrew word is sort of a world unto itself, as these words have formed over the span of thousands of years, and in many cases have hundreds of different layers of meaning stacked on top of them. By just scratching the surface on the Hebrew language, you quickly come to understand why there is so much debate within religious circles regarding Biblical concepts, all due to these multifaceted ancient words.