Q: I often hear “onboard” used in a bureaucratic sense, as in “The entire committee was onboard with the decision to move forward.” However, I’ve looked the word up in my dictionary and it only has it in a nautical sense. Is there such a word? And if so, what does it mean?
A: The American Heritage Dictionary of the English Language (4th ed.) has the word “onboard” both as an adjective (“an onboard child-safety seat”) and as an adverb (“come onboard”). The only definition given is “carried or used aboard a vehicle or vessel.”
But under its entry for “board,” American Heritage lists the phrase “on board” as an idiom meaning either “aboard” or “on the job.” That second meaning (“on the job”) is similar to the now familiar bureaucratic jargon.
Merriam-Webster’s Collegiate Dictionary (11th ed.) has both “onboard” and “on board” (see under “board”) as adjectives.
M-W defines “onboard” as carried within or aboard a vehicle. “On board” is defined as meaning either “aboard” or “in support of a particular objective.” The example given is “needed to get more senators on board for the bill to pass.”
So, the lexicographers at both dictionaries give two separate words, “on board,” for figurative meanings similar to the one you are asking about.
The Oxford English Dictionary hasn’t yet recorded this newer meaning of “on board.” (It does, however, include “board shorts,” the baggy shorts originally worn by surfers, a word born in Australia, circa 1975.)
The OED explains that in common usage, “on board” means on or in a ship or boat. It’s a shortened form of “on ship-board,” a term that’s been around since Middle English (originally, “within schippe burdez”). Here “boards” supposedly means the deck.