Sheikh
Sheikh (from Arabic: شيخ [shaikh or sheikh] 'elder') is a title of Arabic origin, etymologically comparable to the archetype of wise old man.
The use of the Castilian spelling «sheikh» —derived from the Arabic shaij or sheij— has been documented since the XV. Its Islamic meaning is more restricted than that of the Arabic term. Indeed, the Dictionary of the RAE says that a sheikh is, "among Muslims and other oriental peoples, superior or ruler who governs and commands a territory or province, either as sovereign, or as feudatory.» Popularly, the word sheikh is usually associated with the image of the Bedouin chiefs or the potentates of the Arabian peninsula.
And an imam of a mosque is also called sheikh (example: "Sheikh Abdul Hamid kishk"), and they are called sheikh because of what they know about religion or because of a simple respect for his age.
In general terms, a shayj or sheyj (feminine shayja or sheyja) is a person who is respected because of their age or knowledge. In Islam, it often refers generically to men versed in religion (such as alfaqis, ulema, muftis, etc.). In a Sufi brotherhood the shaykh is the spiritual master. Christian Arabs also tend to use it in the same way.
Shaykh is also the head of a Bedouin tribe in the Arabian peninsula, and was used as an official title by the monarchs of Kuwait until the state joined the Arab League in 1961 and adopted the name of emirate (being its leaders then emirs or princes).
In the area of the Persian Gulf, the term is used to refer to prominent people, generally high-ranking politicians or businessmen (in these cases the word "sheikh" is usually used in Spanish).
In Algeria a shayja or sheyja is a teacher in certain forms of singing. The best known outside its borders is Cheikha Remitti.
Too often the title is used as a mere courtesy address addressed to older people. However, its use is delicate since in certain contexts it can be used to show someone that they are or look like an old man. In many places (both in the Arab world and in non-Arab Muslim countries) shaykh has become a proper name. In West Africa, the derivations Cheïkh, Sékou or Cheikou are widely used in this sense.
Etymology
The Arabic word comes from a triliteral root Š-I-J (ش ي خ), related to old age. It later came to mean "lord," "venerable old man," and "noble," especially in Arabia, where "sheikh" became a traditional title for a Bedouin tribal chief in recent centuries. Due to the expansion of Arab civilization and Islam, the term has become global as a religious or simply honorific word in African and Asian Muslim cultures.
Thus the title for Muslims is a religious title for an educated person, as an Arabic word it is a political term independent of religion. It is also widely used by the Druze to designate their priests as well as by Christian Arabs for venerable elders.
It could be equated to the Latin word senex, old man, from which the word senator derives in many languages. In fact, in Arabic, Western senates, such as the US senate, are often called machlis al-shuyuj, “council of elders”.