"The terminology of a “bug” is usually attributed to Grace Hopper in 1945, but this seems to indicate it was in airplane terminology years earlier."<p>??? It goes back to at least Edison. <a href="https://en.wikipedia.org/wiki/Software_bug#History" rel="nofollow">https://en.wikipedia.org/wiki/Software_bug#History</a> quotes him as writing in 1878:<p>> It has been just so in all of my inventions. The first step is an intuition, and comes with a burst, then difficulties arise—this thing gives out and [it is] then that "Bugs"—as such little faults and difficulties are called—show themselves and months of intense watching, study and labor are requisite before commercial success or failure is certainly reached.[3]<p>The Hopper story is "First actual case of bug being found", tongue-in-cheek because the bug was actually caused by a bug, instead of metaphorically so.