苦味酸，化学名2,4,6-三硝基苯酚，字母缩写TNP、PA是一种炸药，名字由希腊语的πικρος（苦味）得来，味道很苦。纯净物室温下呈略带黄色的结晶，难溶于四氯化碳，微溶于二硫化碳，易溶于丙酮、苯等有机溶剂，溶于热水、乙醇、乙醚。它是苯酚的三硝基取代物，受硝基吸电子效应的影响而有很强的酸性。

干燥的苦味酸感度较低，略高于TNT（*****），储存和运输都比较安全。但是某些苦味酸盐的感度较高，因此储存苦味酸必须用非金属容器，装于弹体中的苦味酸必须经过严格的干燥，以阻止苦味酸腐蚀金属，生成高感度的盐。

Picric acid is the chemical compound formally called 2,4,6-trinitrophenol (TNP). This yellow crystalline solid is one of the most acidic phenols and is vinylogous to nitric acid. Like other highly nitrated compounds such as TNT, picric acid is an explosive. Its name comes from the Greek πικρός (pikros), meaning "bitter", reflecting its bitter taste.