What does la ilaha il Allah mean? I know it translates as there is no God but Allah. But what does it MEAN?

there is nothing in the heavens nor on earth that deserves worship except Allah, the One True Creator.

The literal translation is,

"There is no God, but God, and Allah is His Name."

I doubt the meaning could be more unequivocal.

A Christian equivalent might be, "Thou Shalt Have No Other God Besides Me."

I take each to be a warning, against idolatry.

What is meant here is really quite self-explanatory: Allah is the only God. There are no other Gods, as the Greeks, Romans, and other polytheistic religions believe(d).

Allah is the God of Arabic and other monotheistic religious groups.

In social language, it means "I am a Muslim" I guess lol but this coming from an Aspergers person, so i can't really tell you about social language.

But basically it means that you worship Yahweh/Allah/Jehovah alone and you don't believe in Thor or Odin.

It means that there is but one God. Has nothing to do with being Arabic.

It means that no other God, but the Islamic God, exists

if you say it 3 times in front of a Muslim you are officially a Muslim.

cantabile