The phrase "almost secret" is correct and usable in written English.
It can be used to describe something that is not fully secret but is kept hidden or not widely known.
Example: "The club had an almost secret location that only a few members were aware of."
Alternatives: "nearly hidden" or "partially concealed".
Mentions the almost secret plantations of the big rubber producers in the jungles.
And still this small, almost secret restaurant doesn't miss the points of what Brixton culinary life is about: simple, fresh, local and affordable food for all.
But a quick walk away is another, almost secret, park that embodies the scruffy, idealistic side of Asheville: George Washington Carver Edible Park.
Cinedoc is in the Passage Jouffroy, a wonderful almost secret network of covered glazed shopping arcades dating from the 19th century.
Among the myriad museums here, the Musée Guimet is one that people either love with a deep, almost secret passion, or have probably never set foot in.
We also recommend the almost secret spot of the Deep Purple Pool Hall in the Opera House Concert Hall's northern foyer.
It introduces Catherine Gehrig, a conservator and horologist at "one of London's almost-secret treasure houses".
Commis has the feel of an almost-secret experiment in progress.
Luxuriant and overgrown, this almost-secret garden, patrolled by lazily sauntering peacocks and wildfowl, gathers the trees and plants of Asia, Africa and the Americas.
Until the moment at which this book begins, Catherine had her own almost-secret treasure: a love affair with Matthew Tindall, the head curator of metals, whom she knew as "my secret darling".
Soon David's driver was trailing a Port Authority police vehicle that looped around an almost-secret ramp and through Fort Lee, N.J., leading the way to the upper-level toll booths.
