Politicians and media are throwing around the term "quid pro quo" with some now adding the terms "bribery" and "extortion" to be more specific. I looked up the legal definitions of the terms and although quite lengthy, I have extracted the key phrases that might be applicable to the Ukraine quid pro quo:
Quid pro quo -- "Something for something" is a Latin phrase to mean an exchange of goods or services, in which one transfer is contingent upon the other; "a favour for a favour". Phrases with similar meanings include: "give and take", "tit for tat", and "you scratch my back, and I'll scratch yours". The term is commonly applied to legal contracts between two parties but also has usage in sexual harassment cases. When the quid pro quo is illegal, it can be called bribery.
Bribery is the act of giving or receiving something of value in exchange for some kind of influence or action in return, that the recipient would otherwise not offer. Bribery is defined by Black's Law Dictionary as the offering, giving, receiving or soliciting of any item of value to influence the actions of an official or other person in charge of a public or legal duty.
Extortion is obtaining benefit through coercion. It is often used loosely to refer to everyday situations where one person feels indebted against their will, to another, in order to receive an essential service or avoid legal consequences. Extortion involves the verbal or written instillation of fear that something will happen to the victim if they do not comply with the extortionist's will.
Bribery versus Extortion: A charge of extortion need not involve public officials to be made, whereas bribery as a criminal offense involves those employed by the Government, mostly, along with certain clear provisions for cases of bribery in business.
In extortion, the receiver is the initiator of the transaction, as opposed to the giver. But in bribery, the bribee could still be the initiator, instead of the briber. The key difference, then, is that in extortion the extorting individual, the receiver of goods, is not offering anything to the extorted individual, the giver.
Bribery, on the other hand, might involve the bribed individual asking for a bribe from the bribing individual, but in general, the bribed party will then do something in the favor of the bribing party.
The Ukraine quid pro quo can perhaps be summarized as follows:
Zelensky wanted and asked for military aid from the United States to purchase more Javelin anti-tank missiles for defense in Ukraine’s ongoing conflict with Russian-backed separatists in its east. Congress had already approved $391 million in aid. Trump responded to the request in a phone call with these now incriminating words: “I would like you to do us a favor though.”
The favor that Trump wanted was in two parts, 1) Zelensky would initiate an investigation into the bizarre and unfounded theory about Ukrainian possession of a Democratic email server, and 2) he would also initiate an investigation about the Biden family’s dealings in Ukarine. Most importantly to Trump was that he wanted an official statement from Zelensky that they had opened up these investigations, which would play well in the US right wing media.
The quid pro quo is illegal because it required a foreign government to investigate Trump's political opponent in return for military aid already approved by Congress, but put on hold by Trump. It meets the definition of a bribe because Trump wanted Zelensky to manufacture or find dirt (valuable to Trump's reelection) on his political opponent in return for the military aid.
In a sense it might also have elements of extortion because it involved the "verbal instillation of fear that something will happen to the victim" (coercion) if Zelensky did not comply. The Ukraine government desperately needed the military aid fearing Russian incursions on its eastern border and the authoritarian bully Trump exploited that fear with coercion.
Trump therefore appears to be guilty of both bribery and extortion. Let's start calling it that instead of a Latin phrase poorly understood by the populace.