Tunnel vs. Arch — What's the Difference?

A tunnel is an underground passageway, dug through the surrounding soil/earth/rock and enclosed except for entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods.

An arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it. Arches may be synonymous with vaults, but a vault may be distinguished as a continuous arch forming a roof.

An artificial underground passage, especially one built through a hill or under a building, road, or river

A usually curved structure forming the upper edge of an open space and supporting the weight above it, as in a bridge or doorway.

Short for wind tunnel

A structure, such as a freestanding monument, shaped like an inverted U.

A long, half-cylindrical enclosure used to protect plants, made of clear plastic stretched over hoops

A curve with the ends down and the middle up:the arch of a raised eyebrow.

Dig or force a passage underground or through something

(Anatomy)An organ or structure having a curved or bowlike appearance, especially either of two arched sections of the bony structure of the foot.

(of a particle) pass through a potential barrier.

To provide with an arch:arch a passageway.

An underground or underwater passage.

To cause to form an arch or similar curve.

A passage through or under a barrier such as a mountain.

To bend backward:The dancers alternately arched and hunched their backs.

A tube-shaped structure.

To span:"the rude bridge that arched the flood"(Ralph Waldo Emerson).

To make a tunnel through or under

To form an arch or archlike curve:The high fly ball arched toward the stands.

To produce, shape, or dig in the form of a tunnel

Chief; principal

To make a tunnel.

Mischievous; roguish

An underground or underwater passage.

Teasing, ironic, or sardonic

A passage through or under some obstacle.

An inverted U shape.

A hole in the ground made by an animal, a burrow.

An arch-shaped arrangement of trapezoidal stones, designed to redistribute downward force outward.

A wrapper for a protocol that cannot otherwise be used because it is unsupported, blocked, or insecure.

(architecture) An architectural element having the shape of an arch

A vessel with a broad mouth at one end, a pipe or tube at the other, for conveying liquor, fluids, etc., into casks, bottles, or other vessels; a funnel.

Any place covered by an arch; an archway.

The opening of a chimney for the passage of smoke; a flue.

An arc; a part of a curve.

(mining) A level passage driven across the measures, or at right angles to veins which it is desired to reach; distinguished from the drift, or gangway, which is led along the vein when reached by the tunnel.

A natural arch-shaped opening in a rock mass.

(figurative) Anything that resembles a tunnel.

(anatomy) Curved part of the bottom of a foot.

(transitive) To make a tunnel through or under something; to burrow.

(obsolete) chief

(intransitive) To dig a tunnel.

To form into an arch shape.

To transmit something through a tunnel (wrapper for insecure or unsupported protocol).

To cover with an arch or arches.

To insert a catheter into a vein to allow long-term use.

Knowing, clever, mischievous

(physics) To undergo the quantum-mechanical phenomenon where a particle penetrates through a barrier that it classically cannot surmount.

Principal; primary

A vessel with a broad mouth at one end, and a pipe or tube at the other, for conveying liquor, fluids, etc., into casks, bottles, or other vessels; a funnel.

Any part of a curved line.

The opening of a chimney for the passage of smoke; a flue; a funnel.

Usually a curved member made up of separate wedge-shaped solids, with the joints between them disposed in the direction of the radii of the curve; used to support the wall or other weight above an opening. In this sense arches are segmental, round (i. e., semicircular), or pointed.

An artificial passage or archway for conducting canals, roads, or railroads under elevated ground, for the formation of roads under rivers or canals, and the construction of sewers, drains, and the like.

Any place covered by an arch; an archway; as, to pass into the arch of a bridge.

A level passage driven across the measures, or at right angles to veins which it is desired to reach; - distinguished from the drift, or gangway, which is led along the vein when reached by the tunnel.

Any curvature in the form of an arch; as, the arch of the aorta.

To form into a tunnel, or funnel, or to form like a tunnel; as, to tunnel fibrous plants into nests.

A chief.

To catch in a tunnel net.

To cover with an arch or arches.

To make an opening, or a passageway, through or under; as, to tunnel a mountain; to tunnel a river.

To form or bend into the shape of an arch.

To make a tunnel; as, to tunnel under a river.

To form into an arch; to curve.

A passageway through or under something, usually underground (especially one for trains or cars);

Chief; eminent; greatest; principal.

A hole in the ground made by an animal for shelter

Cunning or sly; sportively mischievous; roguish; as, an arch look, word, lad.

Move through by or as by digging;

A curved shape in the vertical plane that spans an opening

Force a way through

A curved bony structure supporting or enclosing organs (especially arches of the feet)

A passageway under an arch

(architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it

Form an arch or curve;

(of persons) highest in rank or authority or office;

(used of behavior or attitude) characteristic of those who treat others with condescension

Expert in skulduggery;