What is mnemonic for "W" in WIFEXITED, WEXITSTATUS, etc?

Question

What is mnemonic for "W" i.e. what does "W" mean in the following macros:

int WIFEXITED (int status)
int WEXITSTATUS (int status)
int WIFSIGNALED (int status)
int WTERMSIG (int status)
int WCOREDUMP (int status)
int WIFSTOPPED (int status)
int WSTOPSIG (int status)

Also see Process Status Completion.

Answer 1

It is simply related to W-aiting functions like the waitpid syscall.

Answer 2

I suspect it's for wait. These constants are for status provided by wait, waitpid, etc. functions.