The mysterious quark is one of the two basic constituents of matter that make up protons and neutrons, with there being exactly three quarks within each kind of particle.
It is often stated that the word was originally coined by Murray Gell-Mann who found it in James Joyce's book Finnegans Wake. However, Joyce himself had probably found the word in a German dictionary.
"Three quarks for Muster Mark!
Sure he has not got much of a bark
And sure any he has it's all beside the mark"
(James Augustine Aloysius Joyce)
"Getretener Quark wird breit, nicht stark"
(Johann Wolfgang von Goethe)