The antonyms for the phrase "putting on board" are numerous, as there are many ways to describe the opposite of adding something to a ship or aircraft. Some possible antonyms may include removing, taking off, unloading, disembarking, or subtracting from the vessel or aircraft. Other antonyms may include disposing, discharging, ejecting, or offloading cargo or passengers from the vehicle. When referring to the opposite of adding something to a group or team, synonyms may include omitting, excluding, rejecting, or dismissing individuals from the organization. In essence, the antonyms for "putting on board" all describe the opposite of adding or including something or someone to a larger unit or system.