Terminology
The terms "pungent" (i/pʌndʒənt/) and "pungency" are rarely used in colloquial speech but are preferred by scientists as they eliminate the potential ambiguity arising from use of the words "hot" and "spicy", which can also refer to temperature and the presence of spices, respectively.
For instance, a pumpkin pie can be both hot (out of the oven) and spicy (due to the common inclusion of spices such as cinnamon, nutmeg, allspice, mace, and cloves), but it is not pungent. (A food critic may nevertheless use the word "piquant" to describe such a pie, especially if it is exceptionally well seasoned.) Conversely, pure capsaicin is pungent, yet it is not naturally accompanied by a hot temperature or spices.
As the Oxford, Collins, and Merriam-Webster dictionaries explain, the term "piquancy" refers to mild pungency and flavors and spices that are much less strong than chilli peppers, including, for example, the strong flavor of some tomatoes. In other words, pungency always refers to a very strong taste whereas piquancy refers to any spices and foods that are "agreeably stimulating to the palate", in other words to food that is spicy in the general sense of "well-spiced".
Read more about this topic: Piquant