transit

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of passing over, across, or through; passage.
2. n. Conveyance of people or goods from one place to another, especially on a local public transportation system.
3. n. The system or vehicles used for such conveyance.
4. n. A transition or change, as to a spiritual existence at death.
5. n. Astronomy The passage of a celestial body across the observer's meridian.
6. n. Astronomy The passage of a smaller celestial body or its shadow across the disk of a larger celestial body.
7. n. A surveying instrument similar to a theodolite that measures horizontal and vertical angles.
8. v. To pass over, across, or through: aircraft transiting the United States and Canada.
9. v. To revolve (the telescope of a surveying transit) about its horizontal transverse axis in order to reverse its direction.
10. v. Astronomy To make a transit.

Century Dictionary and Cyclopedia

1. n. in astronomy, the passage or transit of a star across the meridian at the point opposite to the point of culmination. In the case of a circumpolar star it is often called lower culmination or transit sub polo.
2. On a surveyors’ transit, to turn (the telescope) over so as to make it point, in the opposite direction.
3. n. The act of passing; a passing over or through; a passage; the act of moving, or the state of being conveyed; also, the act or process of causing to pass; conveyance: as, the transit of goods through a country; the problem of rapid transit in cities.
4. n. A line of passage or conveyance through a country: as, the Nicaragua transit.
5. n. In astronomy: The passage of a heavenly body aeross the meridian of any place. The right ascension of such a body is the sidereal time of its upper transit.
6. n. The passage of a celestial body (specifically either of the planets Mercury and Venus) across the sun's disk, or of a satellite, or the shadow of a satellite, across the face of its primary. The passage of the moon across the sun's face, however, is called an eclipse. The planet Mercury passes across the sun's face usually at intervals either of 13 or of 7 years, transits at the planet's ascending node occurring in November, and those at the descending node in May. November transits have occurred or will occur in 1651, 1664, 1677, 1690, 1697, 1710, 1723, 1736, 1743, 1756, 1769, 1776, 1782, 1789, 1802, 1815, 1822, 1835, 1848, 1861, 1868, 1881, 1894, 1907, 1914, 1927, 1940, 1953, 1960, 1973, 1986, 1999, and May transits in 1674, 1707, 1740, 1753, 1786, 1799, 1832, 1845, 1878, 1891, 1924, 1937, 1970, 2003. Owing to the proximity of Mercury to the sun, its transits do not have the astronomical importance of those of Venus, as they are less suitable for determining the solar parallax. Transits of Venus occur at intervals of 8, 122, 8, 105, 8, 122, … years, and always in June or December. They are of great importance to the astronomer, for they afford an excellent method of determining the sun's parallax. The actual calculation of this from a transit is very intricate, as many slight corrections and sources of error have to be considered. The principle involved, however, will be understood from the diagram, in which AB represents the earth, and V and S Venus and the sun. Observers at A and B see Venus projected on the sun's disk at A' and B' respectively, the observations being made simultaneously. The apparent positions A', B' are carefully determined by photography, by micrometric measures, or otherwise; and a subsequent comparison of notes gives the angle adjective If R and τ denote the respective distances of the earth and Venus from the sun, the angle β is given by the equation α: β = τ: R. The ratio τ: R is known with great precision from the sidereal periods of Venus and the earth, and since a was found by observation, the foregoing equation determines β. The angle AB'B (being the angle subtended by the earth's diameter at the sun's distance) is equal to double the solar parallax, or to 2π. From the triangle AVB' it follows that . The transit of 1769 was observed by expeditions sent out expressly for the purpose by the British, French, Russian, and other governments. The celebrated expedition of Captain Cook to Otaheite was one of them. The transits of December 8th, 1874, and December 6th, 1882, were also observed by various government expeditions. The next two transits of Venus will take place on June 8th, 2004, and June 6th, 2012, respectively. The satellites of Mars, Uranus, and Neptune are too small to be seen in transit, and even Titan is an unsatisfactory object to follow across the face of Saturn. Great interest attaches, however, to transits of the satellites of Jupiter, or of the shadows of these satellites. When one of them crosses a dark belt it can usually be followed entirely across the disk as a round shining spot. The brightness of the satellites is variable, however, and sometimes they look like dusky or even black spots when seen against the disk of the planet The transit of a satellite's shadow is readily observed. The shadow may be on the disk when the satellite casting it is off, or the two may be seen on the disk at the same time. The shadows are not always black, but are sometimes so bright as to be invisible. They are often, and perhaps usually, different in size from the satellites casting them; and they have repeatedly been seen elliptical in outline. On a few occasions comets are thought to have been seen in transit.
7. n. An abbreviation of transit-circle or transitinstrument.
8. n. An instrument used in surveying for measuring horizontal angles. It resembles a theodolite, but is not intended for very precise measurement. Most transits read only to the nearest minute of arc, though some read to the nearest half-minute, or twenty seconds, or even ten seconds.
9. To pass over the disk of, as of a heavenly body.

Wiktionary

1. n. The act of passing over, across, or through something.
2. n. The conveyance of people or goods from one place to another, especially on a public transportation system; the vehicles used for such conveyance.
3. n. astronomy The passage of a celestial body across the observer's meridian, or across the disk of a larger celestial body.
4. n. A surveying instrument rather like a theodolite that measures horizontal and vertical angles.
5. n. navigation an imaginary line between two objects whose positions are known. When the navigator sees one object directly in front of the other, then navigator knows that his position is on the transit.
6. n. UK a Ford Transit van.
7. n. Internet to carry communications traffic to and from a customer or another network on a compensation basis as opposed to peerage in which the traffic to and from another network is carried on an equivalency basis or without charge.
8. v. To pass over, across or through something
9. v. To revolve an instrument about its horizontal axis so as to reverse its direction
10. v. astronomy, intransitive To make a transit

GNU Webster's 1913

1. n. The act of passing; passage through or over.
2. n. The act or process of causing to pass; conveyance.
3. n. A line or route of passage or conveyance.
4. n. The passage of a heavenly body over the meridian of a place, or through the field of a telescope.
5. n. The passage of a smaller body across the disk of a larger, as of Venus across the sun's disk, or of a satellite or its shadow across the disk of its primary.
6. n. An instrument resembling a theodolite, used by surveyors and engineers; -- called also transit compass, and surveyor's transit.
7. v. (Astron.) To pass over the disk of (a heavenly body).

WordNet 3.0

1. v. pass across (a sign or house of the zodiac) or pass across (the disk of a celestial body or the meridian of a place)
2. n. a facility consisting of the means and equipment necessary for the movement of passengers or goods
3. v. cause or enable to pass through
4. n. a journey usually by ship
5. n. a surveying instrument for measuring horizontal and vertical angles, consisting of a small telescope mounted on a tripod
6. v. revolve (the telescope of a surveying transit) about its horizontal transverse axis in order to reverse its direction
7. v. make a passage or journey from one place to another