- The definition of a tropic is an area located from 23.5 degrees on the north of the equator down to 23.5 degrees on the south of the equator.
An example of a tropic is the Tropic of Capricorn, the area from the equator to 23.5 degree south of the equator.
- Astron. either of two circles of the celestial sphere parallel to the celestial equator, one, the , c. 23° 26 north, and the other, the , c. 23° 26 south: they are the limits of the apparent north-and-south journey of the sun and are determined by the obliquity of the ecliptic
- Geog. either of two parallels of latitude ( and ) situated on either side of the earth's equator that correspond to the astronomical tropics
Origin of tropicMiddle English tropik ; from Late Latin tropicus ; from Classical Greek tropikos, belonging to a turn (of the sun at the solstices) ; from tropē: see trope
Origin of -tropic; from Classical Greek -tropos, turning (; from trepein: see trope) + -ic
- Either of two parallels of latitude on the earth, one 23°27&minute; north of the equator and the other 23°27&minute; south of the equator, representing the points farthest north and south at which the sun can shine directly overhead and constituting the boundaries of the Tropics.
- Astronomy Either of two corresponding parallels of celestial latitude that are the limits of the apparent northern and southern passages of the sun.
Origin of tropicMiddle English tropik, from Old French tropique, from Late Latin tropicus, from Latin, of a turn, from Greek tropikos, from tropē, a turning; see trep- in Indo-European roots.
Origin of tropicFrom –tropic.
- Turning or changing in a specified way or in response to a specified stimulus: heliotropic.
- Affecting or attracted to something specified: psychotropic.
Origin of -tropicFrom Greek tropē, a turning; see tropic.
(comparative more tropic, superlative most tropic)
- Of, or relating to the tropics; tropical.
- (weather, climate) hot and humid.
- (biochemistry) (noncomparative) Having the quality of indirectly inducing a biological or chemical change in a system or substrate.
- The binding of oxygen to hemoglobin is allosterically regulated by various tropic factors, such as BPG and acidity.
From Late Latin tropicus (“of or pertaining to the solstice, as a noun, one of the tropics”), from τροπικός (tropikós, “of or pertaining to a turn or change, or the solstice, or a trope or figure, tropic, tropical; etc.”), from τροπή (tropē, “a turn, turning, solstice, trope”); see trope.