under wraps
adj.— «Stevie Wonderboy’s performance was so dominating that the victory was completed with jockey Garrett Gomez having a firm hold on the reins—”under wraps” in racing parlance—because having the colt further extend himself was obviously unnecessary.» —“It’s a wondrous end to Del Mar’s $608 million meet” by Hank Wesch in Del Mar Union-Tribune (San Diego, California) Sept. 8, 2005. (source: Double-Tongued Dictionary)
Further reading
What if, instead of being an inanimate object, a dictionary were alive? That’s the idea behind a lavishly illustrated new children’s book called The Dictionary Story (Bookshop|Amazon) by Oliver Jeffers and Sam Winston. This is part of a...
Jim in Columbia, South Carolina, has noticed sportscasters’ use of the phrase on the season with reference to a period of time. This construction shows up in the sports pages as early as the 1880s, first referring to a team’s revenue and...