Lynx isn't an acronym. It is a name with a deep connection to the history of Astronomy.
Galileo Galilei (1564-1642) was a proud member of Italy's Accademia dei Lincei (Academy of the Lynx), a scientific society devoted to investigations of the natural world. Federico Cesi, who founded the "Lincean Academy" in 1603, named it after the lynx, whose sharp vision evokes the observational prowess on which scientific progress relies. It was in one early meeting of the academy that the term "telescope" was first coined. The Lincean Academy exists to this day as the Accademia Nazionale dei Lincei, effectively serving as Italy's National Academy of Science.
The lynx is a feline with keen eyesight and, in many cultures and traditions, is a symbol of great insight and the supernatural ability to see through to the true nature of things.
Our mission concept was originally dubbed the "X-ray Surveyor", but our team felt that Lynx was a perfect name to evoke the major scientific themes of our mission, all of which relate to the "unseen" or the "invisbile".
That the name ended with an "X" didn't hurt, either.