Nepotism is the showing of favoritism towards relatives, based upon that relationship, rather than on an objective evaluation of ability or suitability. For instance, offering employment to a relative, despite the fact that there are others who are better qualified and willing to perform the job, would be considered a form of nepotism. The word nepotism is from the Latin word 'nepos', meaning "nephew" or "grandchild".
The popular British English expression "Bob's your uncle" is often thought to have originated when Robert Arthur Talbot Gascoyne-Cecil, 3rd Marquess of Salisbury promoted his nephew, Arthur Balfour, to the esteemed post of Chief Secretary for Ireland in what was widely seen as an act of nepotism.