Overstate, exaggerate, magnify, overemphasize, amplify are some of the antonyms for the word "under-play." These words are perfect in situations when one needs to draw attention to something and wants to avoid downplaying or minimizing it. Overstating something can create a dramatic effect, provoke a reaction, or emphasize its importance. The opposite of underplay can be seen in movies or TV shows where actors overplay a scene to heighten its emotional impact. Similarly, in a professional setting where one wants to stress the significance of a project or idea, amplifying its significance can help secure buy-in from stakeholders.