Malfunction
Any failure of a firearm to fire, feed, extract, or eject as intended.
Also: jam, stoppage
A malfunction (or stoppage) is anything that interrupts the firing cycle: failure to fire, failure to extract, failure to eject, double feed, out of battery. Each has a specific cause and correction. The first response to most malfunctions is tap-rack-bang (or tap-rack-assess in defensive contexts).