1. Adverb.  On board; into or within a ship or boat; hence, into or within a railway car.
  2. Adverb.  (nautical) Alongside.
  3. Adverb.  (baseball) on base.
  4. Preposition.  On board of; as, to go ''aboard'' a ship.
  5. Preposition.  (obsolete) Across; athwart.

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This entry was last updated on RefTopia from its source on 3/20/2012.