[{"Bold_text": "adverb", "List Items": ["on board; on, in, or into a ship, train, airplane, bus, etc.:to step aboard.", "alongside; to the side.", "Baseball.on base:a homer with two aboard.", "into a group as a new member:The office manager welcomed him aboard."]}, {"Bold_text": "preposition", "List Items": ["on board of; on, in, or into:to come aboard a ship."]}]