The phrase "almost entirely open" is correct and usable in written English.
It can be used to describe a situation, space, or concept that is mostly, but not completely, open or accessible.
Example: "The park was almost entirely open, allowing for a clear view of the surrounding mountains."
Alternatives: "nearly completely open" or "mostly open".
The interior is almost entirely open, centered around a living and dining area with a massive oak table, an Italian leather couch and a floor-to-ceiling bookcase.
And that's after the speaker clamped down on the process, restricting which amendments could be offered to bills, something Boehner was able to avoid with a process that was almost entirely open.
In group N (without lung disorders), the Pao2/Fio2 ratio at 5 cmH2O PEEP was already 49.7 kPa (373 Torr), indicating that the lung was almost entirely open at this PEEP level and therefore application of higher PEEP levels would only further inflate the already open alveoli.
"Launched initially as an almost entirely open-source operating system, Google has over time moved more and more apps and Android software elements into a proprietary Google license".
In contrast, Yahoo has been an extensive contributor and has built its internal computing platform almost entirely from open source.
While Bush is competing against more than a dozen Republicans, Clinton's field-clearing presence has left the path to the Democratic nomination almost entirely wide open.
This year Costco expects to add 1,500 to 2,000 workers, based almost entirely on opening new retail warehouses.
Craigslist runs almost entirely on open-source software which, Buckmaster noted, is "free and progressively better every month".
The almost entirely sustainable winery opened in 2008 and has a sleek tasting room at the base of a hill surrounded by vineyards.
Yesterday was almost entirely about the Opening (capital "o" essential) Ceremony (capital "c" ditto), scheduled to begin at the unfeasibly late hour of 9pm – unfeasible, certainly, if you recall that Bruce Springsteen had the plug pulled on him a couple of weeks back.
The TraPac terminal, staffed almost entirely by robots, opened in the L.A. port 17 months ago.
