Jet (as in a jet of water) showed up in English in the 1690s. It came through French from the Latin word iacere, which meant to throw. It doesn’t take much creativity to imagine how a word meaning to throw would end up referring to:
a stream of water (1690),
a spout or nozzle for emitting fuel (1825),
jet propulsion (1855 – no joke – at that point we were propelling things with jets of water), or
fuel-driven jet propulsion (1945).
What fascinates me are all the other words that came from iacere.
jetty – early 1400s – rocks or land thrown into the sea
jetsam – 1560s – initially the act of throwing something overboard, soon to morph into the items thrown overboard
jettison – 1848 – to throw overboard
trajectory – 1690s – the path of something thrown
adjective – late 1300s – from ad-iacere, meaning to throw near
adjacent – late 1400s – also from ad-iacere, meaning to throw near
jut – mid 1400s – throw in the way
eject – mid 1400s – to throw out
joist – early 1300s – lumber thrown down on which a floor can be built
interjection – early 1400s – a word thrown into a conversation
conjecture – late 1300s – a possibility one throws into an argument
As you consider the next list of words, imagine how they might have something to do with the Latin root iacere, to throw, then click on comments below & offer your explanation of the connection.