Linguistic definition: exerting one's efforts in order to fulfill a certain goal.
Islamic definition: A Muslim exerting his/her efforts and abilities seeking the pleasure of Almighty God.
In the linguistic sense, the Arabic word "jihad" means struggling or striving and applies to any effort exerted by anyone. In this sense a student struggles and strives to get an education and pass course work; an employee strives to fulfill his/her job and maintain good relations with his/her employer; a politician strives to maintain or increase his popularity with his constituents and so on. The term strive or struggle may be used for/by Muslims as well as non-Muslims;
In the West, jihad is generally translated as holy war- a usage the media has popularized unknown to Islamic texts. According to Islamic teachings, it is unholy to instigate or start war; however, some wars are inevitable and justifiable. If we translate the words holy war into Arabic we get "harbun muqaddasatun" or for the holy war "al-harbu al-muqaddasatu". We challenge any researcher or scholar to find this word in the Qur'an, authentic Hadith collections, or in the first few centuries Islamic literature. Unfortunately, some Muslim writers and translators of the Qur'an, the Hadith and other Islamic literature translate the term jihad as holy war, due to the influence of Western propaganda. This could be a reflection of the Christian use of the term "Holy War" to refer to the Crusades of a thousand years ago. However, the Arabic words for "war" are "harb" or "qital", which are found in the Qur'an and Hadith.
For Muslims the term jihad is applied to all forms of striving and has developed some special meanings over time. The sources of this development are the Qur'an (the Word of God revealed to Prophet Muhammad) and the Hadith (teachings of Prophet Muhammad (pbuh) guided by God).