These words refer to things that are not smooth or straight. Rough and uneven are both very general and vague in their implications. Rough can specifically indicate a coarse-grained surface: rough sandpaper. At its most specific, uneven suggests something, such as a line, configuration or surface, that has more noticeable ups and downs: an uneven margin; uneven landscape. Rough , however, may also indicate irregular or uneven ground that is impenetrable, steep or difficult to traverse: rough terrain. Less concretely, the word can indicate anything unrefined, harsh or difficult: a rough sketch; rough treatment; rough wine; a rough job. The last use approaches slang in its informality. In its other uses, uneven stays closer to its reference to something with irregular variations: uneven patches of shrubbery scattered across the lawns; an amusing but uneven play. It can refer also to something unsymmetrical, unmatched or disarranged: a face with uneven features; The pictures on the walls were slightly uneven in placement.

Bumpy , rugged and corrugated are much more specific in their reference to rough or uneven surfaces. Rugged applied mostly to landscape, stressing an extremely uneven topography or a resistance to smooth passage: rugged mountains; rugged waves; a rugged dirt road. The word carries implications of harshness or toughness, as can be seen in more general uses of the word: a rugged , masculine build. Bumpy can refer to smaller-scale surfaces as well as to landscape. In both cases, the word may suggest a generally smooth stretch that is nevertheless filled with small hollows and lumpy projections: After an hour of sanding, the boards were still quite bumpy . Often, the word refers to anything that results in travel that is full of jolts: a bumpy road enclosed by rugged hills; Our jet picked its way through air pockets that made the flight extremely bumpy . Corrugated refers to a more even series of bumps, sometimes by design, as with corrugated iron or asbestos for roofing. In another specific use it applies to a road surface in which regular small bumps have developed in a lateral direction, so that a car is badly shaken.

Crooked specifically refers to undesirable departures, great or small, from the horizontal or vertical.

• All the pictures on the wall were crooked ; a crooked tower; The seams of her stockings were crooked .

In more general uses, the word can refer to anything skewed, much like uneven : crooked shelves. Occasionally, the word can be used with poetic force to describe something that is naturally uneven or rugged: a range of crooked mountains. Jagged can also be used in this way, particularly of steep or extremely uneven topography: the jagged lip of the crater. More specifically, the word refers to small-scale shapes with sharp or needle-like edges such as those that result when something brittle is broken or shattered: the jagged edges of the broken bone; jagged pieces of glass. As in the last example, the word can refer primarily to an uneven configuration rather than to rough surfaces.

Serrated and crenellated are the most technical and specific of these words. Serrated refers to any saw-toothed configuration or edge: a serrated knife. Crenellated refers most specifically to the regular notched upper edge that is typical of battlements: crenellated castle walls. It can apply more widely to any edge with deep notches: leave distinguished by their crenellated edges.