Is Allah an English word too? Means God?
No. It is only used when discussing Islam, or when quoting the speech of Muslim people. If you use it in any other context, people will assume that you are a Muslim. It is regarded as a foreign name: the Arabic translation of "God."
In English, the word/name "God" is most commonly used, even by those of us who regard God as just a metaphor, legend, fairytale, etc. Christian people also frequently call him "the Lord," sometimes "the Almighty," "the Father" or "our Father," and especially when speaking directly to him in prayer, simply "Father."
In some Christian congregations he is known as "Jehovah." This is the Latin
transliteration of the Hebrew name "Yahweh"
יהוה, with arbitrary vowels inserted because in Hebrew (as in all the Afroasiatic languages including Amharic, Arabic, Egyptian, etc.) vowels are not phonemic and have no effect on meaning, and therefore are not written. "Jehovah" was pronounced "Ye-ho-wah" in Classical Latin, but today we pronounce it "Je-ho-va," a name the ancient Hebrews would not recognize. No one knows which vowels they might have used, and in fact they would have deliberately attempted to use the wrong ones because they believed it was a horrible sin to say God's name aloud and he would have killed anyone who did so. Apparently "Yahweh" is not the correct pronunciation because no one has ever been reduced to a pile of ashes for speaking it.
El and the longer form
eloh are also Hebrew words meaning "God," and they invoke no punishment. The component "-el" in Hebrew names means "God," as in Micha-el: "Who resembles God?" Isra-el: "Triumphant with God" or "Wrestles with God," Jo-el: "Yahweh is God," and Ezeki-el: "God will strengthen."
Eloh is the same word as Arabic
allah, with vowels substituted almost randomly in the Afroasiatic linguistic tradition. In the older classical dialects of those languages both names begin with a glottal consonant which is no longer pronounced.
The Rastafarians use a shortened version of Jehovah/Yahweh and almost always refer to God as Jah. They did not invent this, you can see it in the ancient Hebrew exclamation,
Hallelujah, "(may you all) praise God."
My favorite is the Spanish "ojalá que" which means 'I hope that' followed by whatever one hopes for. It derives from 'O Allah', or an invocation to god. Arrived in Spain from the Moorish invasion.
Note the accent on the third syllable, pronounced o-kha-LA. The Portuguese have it too, spelled
Oxalá and pronounced o-sha-LA.