It is the point in the Earth's orbit when it is closest to the Sun (147.5 million km). Perihelion occurs on the 3rd or 4th of January.

The point on the annual orbit of a body (about the sun) that is closest to the sun; at present, the earth reaches this point on about 5 January. Opposite of aphelion.

"point at which a celestial body is nearest the Sun," 1680s, coined in Modern Latin (perihelium) by Kepler (1596) from Latinizations of Greek peri "near" (see peri-) + helios " [..]

The point in the orbit of a planet or other body where it is closest to the Sun.

The point on the earth's orbit that is nearest the sun. At present, the earth reaches this point on about 1 January, but the date varies irregularly from year to year (due to leap years) and also [..]

the point in the Earth's orbit when it is closest to the sun (147.5 million km). Perihelion occurs on the 3rd or 4th of January. The opposite of Aphelion.

The point in a planet's orbit when it is nearest to the Sun.

— The closest point to the Sun in a planetary body's orbit.

The point in orbit of a planet or a comet nearest the sun (point A).

(n) periapsis in solar orbit; the point in the orbit of a planet or comet where it is nearest to the sun

The point in a planet's orbit that is closest to the Sun (Lesson 29)

That orbital point nearest the Sun, when the Sun is the center of attraction, as opposed to aphelion.

 the point nearest the sun in the orbit of a celestial body

The perihelion is the point in the Earth's orbit that is the closest to the Sun. See sections 2.1.3.1 and 5.4.1. See also aphelion.

The point in the orbit of a planet which is nearest to the Sun. See also aphelion.

The point in a planet's orbit when it is closest to the Sun (Helios is Greek for Sun). See aphelion, perigee

That point, in orbit of a solar system body, at which it comes nearest to Sun.

the orbital point nearest the sun when the sun is the center of attraction (as in the case of a planet)

The point in the orbit of a planet or comet which is nearest the Sun (as opposed to the aphelion, which is the point in the orbit farthest from the Sun).

Point in the elliptical orbit of a comet, or asteroid, or planet about the Sun in which it reaches its closest approach to the Sun. The opposite orbital position is called aphelion.

That orbital point nearest the sun when the sun is the center of attraction. That point farthest from the sun is called APHELION.

The point on the annual orbit of a body (about the sun) that is closest to the sun; at present, the earth reaches this point on about 5 January. Opposite of aphelion.

Position of an object, or body, when it is closest to the sun.

That point on the orbit of a Sun-orbiting body nearest to the Sun. Compare aphelion. definition courtesy of: NWS Space Weather Prediction Center

The point of the earth's orbit that is nearest to the sun. Although the position is part of a 21,000 year cycle, currently it occurs around January, when the earth is about 3 million miles closer [..]

The time of the year when the Earth’s orbital path brings it closest to the sun (about 3 January).

the point in the orbit of a planet at which the planet is closest to the sun

The point of the earth's orbit that is nearest to the sun. Although the position is part of a 21,000 year cycle, currently it occurs around January, when the earth is about 3 million miles closer [..]

The point of the earth's orbit that is nearest to the sun. Although the position is part of a 21,000 year cycle, currently it occurs around January, when the earth is about 3 million miles closer to the sun than at aphelion

The point in its orbit where a body traveling round the Sun is closest to the Sun.

The point on the annual orbit of a body (about the sun) that is closest to the sun; at present, the earth reaches this point on about 5 January. Opposite of aphelion.

The point of the earth’s orbit that is nearest to the sun. Although the position is part of a 21,000 year cycle, currently it occurs around January, when the earth is about 3 million miles closer to the sun than at aphelion. This term can be applied to any other celestial body in orbit around the sun. It is the opposite of aphelion.