If you ask KRunner to define two words surrounded by double quotes (for example by writing define "word1 word2") it (or plasmashell if you use kickoff for the query) it hangs.
STEPS TO REPRODUCE
1. Open KRunner or Kickoff
2. Type in define "word1 word2"
3. Try to close the dialog or enter something else in
KRunner/Plasmashell (depending on where you entered the query) hangs
IT shows no results and everything continues to function as normal
Operating System: Fedora Linux 35 (KDE Spin)
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.2
Fixed by https://invent.kde.org/plasma/kdeplasma-addons/-/merge_requests/132