Meaning "poor quality." With regard to software, jank generally refers to unresponsive scrolling or tapping on touchscreens, which occurs because of excessive processing in the background. When users scroll and tap without a response, they often repeat the action several times. Those inputs accumulate and deliver unexpected screen results when the CPU finally catches up and processes all of them at once. See junkware.
(jargon, computing, rare) Problematic blocking of a software application's user interface due to slow operations.
Origin of jank
- Ostensibly back-formation from janky (“shoddy, poor quality”).