the loache, in ichthyology, a genus of fishes belonging to the order of abdominales. The eyes are in the upper part of the head. The branchiole membrane has from four to five rays; and the body is nearly of an equal thickness throughout. The species are five; three of which are natives of Europe. The loache is found in several of our small rivers, keeping at the bottom on the gravel; and is, on that account, in some places called the groundling. It is frequent in the stream near Amelbury in Wiltshire, where the sportsmen, thro' frolic, swallow it down alive in a glass of white-wine.