Like the phrase ‘high crimes and misdemeanours’ the term ‘bribery’ is not specifically defined in the Constitution.
Founder Gouverneur Morris said, “(The President) may be bribed by a greater interest to betray his trust, and no one would say that we ought to expose ourselves to the danger of seeing the first Magistrate in foreign pay without being able to guard (against) it by displacing him.”
The federal government did not define bribery in a statute until 1853.
At the time of the writing of the Constitution, the Founders would have understood ‘bribery’ as an officeholder abusing the power of office to obtain a private benefit rather than for the public interest, as in English law.
In cases of bribery, the party receiving a bribe will do something in favor of the party who offers the bribe.
Closely related to ‘bribery’ is ‘extortion’.
In extortion, the party that receives something of value does so by making a threat towards the extorted party. That is, the extortionist threatens to perform a certain action that will harm the extorted party unless the extorted party gives the extortionist whatever is demanded.
Extortion is synonymous with blackmail.
The Founders cynical concern about corruption in some future presidency has proven to be sadly prophetic.