Collins defines predate (third meaning) as
to be or occur at an earlier date than; precede in time
The same dictionary defines antedate (first meaning) as
to be or occur at an earlier date than
While there are other meanings for both words, I'd like to know if there is a difference in their usage, when they're used to mean "occur at an earlier date," or if they can always be used interchangeably in this sense.
Best Answer
Merriam-Webster's Eleventh Collegiate Dictionary (2003) provides these definitions for antedate:
and this one for predate:
Roughly the same definitions of antedate and the explicit equating of predate with, simply, "antedate" go back to the Fifth Collegiate (1936). This suggests that, with regard to the senses covered by the longtime definitions of antedate, there is no meaningful difference in usage.
Meanwhile, in the 70 years between 1936 and 2005, the relative popularity of the two terms changed considerably, as this Ngram chart for antedated (blue line) versus predated (red line) illustrates:
Although the decline in antedated seems to mirror the rise in predated, a confounding variable is at work: use of predated as a past tense of predate in the sense of "acted as a predator upon"—a meaning that Merriam-Webster as yet does not officially acknowledge, but that is not at all rare in recent Google Books matches such as this one, from Folia Zoologica, volume 53 (2004) [snippet]:
Still, predator predating notwithstanding, the frequency of antedated has fallen considerably since 1940, and the frequency of predated has risen quite a bit, so it appears that the popular preference has shifted in the past 70 years from antedate to predate.
Two years before Merriam-Webster's first sighting of predate, Westland Marston, The Family Credit, and Other Tales (1862) included this instance of antedated:
But today, an author describing the same scene might be at least as likely to use predated.