Bitter tasting; picric acid.
[Greek pikros, bitter.]
Picrotoxin is a bitter compound sometimes used to stimulate the respiratory and nervous system. A few minerals containing magnesium are named using this form, as magnesium compounds are often bitter tasting; an example is picrite, a dark basaltic igneous rock rich in olivine.
Picric acid, also known as trinitrophenol, is a bitter yellow compound used as a dye and in the manufacture of explosives; some words in picro- refer specifically to its derivatives: it forms salts called picrates and its anion —C6H2(NO2)3 is the picryl group; picramic acid is a derivative used to make azo dyes.