secular
adj.— «In Wall Street parlance, a very long period of falling or, at best, sideways-moving stock prices is termed a “secular” bear market. And there have been some doozies in relatively recent U.S. history.» —“What to do if stocks’ troubles go on…and on” by Tom Petruno Los Angeles Times (California) June 28, 2008. (source: Double-Tongued Dictionary)
Further reading
In 1916, a small-town newspaper in Pennsylvania printed a fanciful item about a local gathering with a guest list that included, among others, Miss Ella Vader, Mr. Ray Zor, and other punny names. This is part of a complete episode. Transcript of...
Arthur in New Bern, North Carolina, wonders why we say something that isn’t difficult is as easy as pie when making a pie is a whole lot of work. This phrase most likely refers to the ease of eating a pie, not making one. This is part of a...
I believe this is just OED sense 8 of secular:
“Econ. and Statistics. Of a fluctuation or trend: occurring or persisting over an unlimited period; not periodic or short-term.”