jet [LME] The name jet for a hard black semi-precious mineral comes ultimately from the Greek word gagatēs ‘from Gagai’, a town in Asia Minor. When we refer to a jet of water or gas, or a jet aircraft, we are using a quite different word also Late Middle English. It comes from a verb meaning ‘to jut out’, from French jeter ‘to throw’, which goes back to the Latin jacere ‘to throw’. Jut [M16th] is a variant of jet in this sense. Jacere is found in a large number of English words including abject [LME] literally ‘thrown away’; conjecture [LME] ‘throw together’; deject [LME] ‘thrown down’; ejaculate [L16th] from jaculum ‘dart, something thrown’; eject [LME] ‘throw out’; inject [L16th] ‘throw in’; jetty [LME] something thrown out into the water; project [LME] ‘throw forth’; subject [ME] ‘thrown under’; trajectory [LME] ‘something thrown across’. Especially if you use budget airlines, air travel today is far from glamorous, but in the 1950s the idea of flying abroad by jet aircraft was new and sophisticated. At the start of that decade people who flew for pleasure came to be known as the jet set.