What does Boxing Day have to do with boxing?
c.1200, "continue, persevere," from Anglo-French suer "follow after, continue," from Old French sivre, later suivre "pursue, follow after," from Vulgar Latin *sequere "follow," from Latin sequi "follow" (see sequel). Sense of "start a lawsuit against" first recorded c.1300, on notion of "following up" a matter in court. Sometimes short for ensue or pursue. Related: Sued; suing.
The system language used to write an operating system for the IBM 360. It is a cross between Pascal and XPL. It allows type checked separate compilation of internal procedures using a program library.
["The System Language for Project Sue", B.L. Clark e al, SIGPLAN Notices 6(9):79-88 (Oct 1971)].