aboard

Aboard is a preposition and adverb meaning on or into a vehicle, vessel, or other conveyance. It indicates presence on the deck or within the confines of a craft, such as a ship, airplane, train, or bus. In modern, non-nautical writing, on board is often preferred, but aboard remains common in nautical, ceremonial, or formal contexts. Examples: "The passengers were aboard the ferry" and "Welcome aboard the ship." The exclamation "All aboard!" is used to call passengers to embark.

Etymology and history: Aboard originates from the phrase on board, where board refers to the wooden deck or planking of a vessel. The form developed into a single word and retained its sense of being on or within a craft. The term is most closely associated with nautical language but has broadened in use over time.

Usage notes: As a word, aboard is typically used as a preposition or adverb before the noun it governs, e.g., aboard the vessel or aboard the plane. It is not a verb. It does not typically take a hyphen. In many contexts, on board and aboard are interchangeable, though aboard can convey a nautical or formal tone and may appear more in ceremonial or official language.

See also: on board, boarding, all aboard. Related phrases emphasize the act of entering or being inside a vehicle, while aboard specifically locates that presence on a craft.