The story
From the name of the C language (on which it was based) and --, the decrement operator in both languages, coined as an inside joke, indicating that C-- is a reduced form of C.
Etymology from Wiktionary, CC BY-SA 4.0.
C--
Today it means: A C-like programming language, designed to be generated mainly by compilers for high-level languages rather than written by human programmers. Full definition →