quid pro quo

The misunderstanding of the word or the quid pro quo is the unintentional pun, and is related to it exactly as folly is to wit.

a knave Apothecary that administers the Physick, and makes the medicine, may doe infinite harme, by his old obsolete doses, adulterine druggs, bad mixtures, quid pro quo, etc.

To him I offered a quid pro quo; and meant to give nothing without getting a full equivalent.

Mr. P. did not consider that branch, strictly and technically speaking, public revenue; at least it did not arise from taxation, because those persons who had paid this money had received a full equivalent for the same; there was a quid pro quo on both sides; and this was not taxation, it was a sale; the parties therefore from whom this money was derived had not been taxed.

A quid pro quo complaint typically is lodged by an employee who has been denied opportunities because he or she refused a perpetrator's sexual advances or by an employee who has been denied opportunities because another employee obtained those opportunities by submitting to a perpetrator's sexual advances.