What does "ilah" mean?

What is the meaning of the Arabic word "ilah"?

Ilah means the absolute entity whom is worshipped, whom is loved more than anything, whom respected and glorified.

As well as the lexical meaning of ilah that is to cover, to hide, to adjust and worship; it has become the common name of the objects that are worshipped and adored.  However, the tawheed doctrine of Islam acknowledges Allah only  to be worshipped, to be adored, to be the Creator of the universe and the matter. So the name “Allah” is the proper name of the God concept that is accepted in Islam. In other words, while Allah is a proper name used for the one God in Islam, “ilah” is a common name refers to God concept in any belief.

The word ilah is also used in the Quran twice. First use refers to the general concept that people worship in a right manner or not. The second refers to the entity who really deserves to be worshipped, the true One God.

“And (they) were not ordered except to give their 'ibadah to one Ilah, only; there is no ilah except He, (and) He is free of (the taint of) what they attribute to Him by their shirk (that is, by associating others with Him in His exclusive qualities and attributes).” ( Surat al Tawbah, 31)

“Those unto whom they cry beside Allah created naught, but are themselves created.

 (They are) dead, not living. And they know not when they will be raised.

Your God is One God. But as for those who believe not in the Hereafter their hearts refuse to know, for they are proud. (Surah al Nahl, 20- 22)

The God doctrine mentioned in the Quran and the hadiths depends on the fact that He is not only the Ilah of the Muslims, but also the Ilah of all the realms. As stated in many verses, all creatures intentionally or unintentionally submit and worship Him.  (Shamil Islamic Encyclopedia)