What is "bypass"

also by-pass, 1848, of certain pipes in a gasworks, from by + pass (n.). First used 1922 for "road for the relief of congestion;" figurative sense is from 1928. The heart operation was first so called 1957.

1823, "to pass by" (implied in bypassed), from bypass (n.). From 1928 as "to go around, avoid;" figurative use from 1941. Related: Bypassed; bypassing.\n\n

n. 1 a road that passes around something, such as a residential area 2 a circumvention 3 a section of pipe that conducts a fluid around some other fixture 4 an electrical shunt 5 (context medicine English) an alternative passage created to divert a bodily fluid around a damaged organ; the surgical procedure to construct such a bypass vb. 1 to avoid an obstacle etc, by constructing or using a bypass 2 to ignore the usual channels or procedures

1. n. a road that takes traffic around the edge of a town [syn: circumferential, ring road]

2. a surgically created shunt (usually around a damaged part)

3. a conductor having low resistance in parallel with another device to divert a fraction of the current [syn: shunt, electrical shunt]

4. v. avoid something unpleasant or laborious; "You cannot bypass these rules!" [syn: short-circuit, go around, get around]

5. [also: bypast]

Bypass may refer to:

• Bypass (audio), in effects units, a switch that allows sound
• Bypass (computing), in computing, circumventing security features in hacking, or taking a different approach to an issue in troubleshooting
• Bypass (road)
• Bypass surgery
• Bypass (telecommunications)
• Bypass (valve)
• Bypass capacitor, used to bypass a power supply or other high impedance component
• High bypass, a turbofan aircraft gas turbine engine
  • Bypass duct
  • Bypass ratio
• Bleach bypass, an optical effect
• Bypass switch

A bypass is a road or highway that avoids or "bypasses" a built-up area, town, or village, to let through traffic flow without interference from local traffic, to reduce congestion in the built-up area, and to improve road safety. A bypass specifically designated for trucks may be called a truck route.

If there are no strong land use controls, buildings are often built in town along a bypass, converting it into an ordinary town road, and the bypass may eventually become as congested as the local streets it was intended to avoid. Petrol stations, shopping centres and some other businesses are often built there for ease of access, while homes are often avoided for noise reasons.

Bypass routes are often controversial, as they require the building of a road carrying heavy traffic where no road previously existed. This creates a conflict between those who support a bypass to reduce congestion in a built up area, and those who oppose the development of (often rural) undeveloped land. However, those of the bypassed city may also oppose the project, as the reduced traffic could damage business.

In telecommunications, the term bypass has these meanings:

1. The use of any telecommunications facilities or services that circumvents those of the local exchange common carrier. Note: Bypass facilities or services may be either customer-provided or vendor-supplied.
2. An alternate circuit that is routed around equipment or a system component. Note: Bypasses are often used to let system operation continue when the bypassed equipment or a system component is inoperable or unavailable.

Source: Federal Standard 1037C and MIL-STD-188

In rebreather breathing sets, a bypass is a hand-operated valve that can be used to let more oxygen (or other breathing gas) into the breathing system, by-passing the cylinder's flow rate control valve.

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