an act, result, of cutting; opening made by a knife or other sharp-edged tool etc

incision

a long cut in the ground made by a plough; a long wrinkle on the forehead

ditch

a long, hollow area in the surface of a hard material, especially one made for something that slides along it, e.g. a sliding door or window

channel, indentation

to break into the edge or surface of (something); to start (a line of print or writing) farther from the margin than the others

make a space; push in slightly

a V-shaped cut

indentation

a deep line or track (as if) made by wheels in soft ground; a way of doing something, behaving, living etc that has become (too) established

groove, indentation