the loache, in ichthyology, a genus of fishes belonging to the order of abominables. The eyes are in the upper part of the head; the branchiofuge 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 Amersham in Buckinghamshire, where the sportmen, through frolic, swallow it down alive in a glass of white wine.