So is that the point you were originally trying to make instead of discussing etymology? While we're quibbling prescriptively about terminology, I'd argue that the IE exploit patched earlier this week was in fact a zero day since it was not public knowledge.
> The vulnerability underlying CVE-2013-3897 was found internally at Microsoft and would have been fixed in MS13-080. However, in the last two weeks, attacks against the same vulnerability became public, but since the fix was in the code already, it enabled Microsoft to address the vulnerability, CVE-2013-3897, in record time.
