/pim"peuhr nel', -nl/ , n.
a plant belonging to the genus Anagallis, of the primrose family, esp. A. arvensis (scarlet pimpernel) , having scarlet or white flowers that close at the approach of bad weather.
[ 1400-50; late ME pympernele pimprenelle, nasalized var. of OF piprenelle piperinella, equiv. to piper PEPPER + -in- -INE 1 + -ella dim. suffix; r. OE pipeneale pipinella, syncopated var. of * piperinella ]