Yes, I know that \"cdecl\" is the name of a prominent calling convention, so please don\'t explain calling conventions to me. What I\'m asking is what the abbreviation (?) \"cd
You're reading too much into this. It stands for the calling convention of the implementation for calling C functions in general (but especially important with varargs).
It doesn't have to be an abbreviation for something that combines "C" and "declaration"; names are just names, especially in programming. Mnemonics help, but even though "malloc" means "allocate memory", it has additional meaning that we know and attach to it; "alloca" also "allocates memory", for example.
Or take "struct" which "means" a "structure", but "structure" is so generic by itself that without the meaning we attach subconsciously to "struct" we would be hopelessly lost – as new programmers still learning the terminology are often lost.