tropic

¹ American  

[trop-ik] / ˈtrɒp ɪk /

noun

1. Geography.

   1. either of two corresponding parallels of latitude on the terrestrial globe, one tropic of Cancer about 23½° N, and the other tropic of Capricorn about 23½° S of the equator, being the boundaries of the Torrid Zone.

   2. the tropics, the regions lying between and near these parallels of latitude; the Torrid Zone and neighboring regions.

2. Astronomy. either of two circles on the celestial sphere, one lying in the same plane as the tropic of Cancer, the other in the same plane as the tropic of Capricorn.

---

adjective

1. of, pertaining to, characteristic of, or occurring in the tropics; tropical.

   romance under the tropic skies of Old Mexico.

-tropic ² American  

1. a combining form with the meanings “turned toward, with an orientation toward” that specified by the initial element (geotropic ), “having an affinity for, affecting” what is specified (lipotropic; neurotropic; psychotropic ), “affecting the activity of, maintaining” a specified organ (gonadotropic ).

---

-tropic ¹ British  

combining form

1. turning or developing in response to a certain stimulus

   heliotropic

---

tropic ² British  

/ ˈtrɒpɪk /

noun

1. (sometimes capital) either of the parallel lines of latitude at about 23 1/ 2 °N ( tropic of Cancer ) and 23 1/ 2 °S ( tropic of Capricorn ) of the equator

2. (often capital) that part of the earth's surface between the tropics of Cancer and Capricorn; the Torrid Zone

3. astronomy either of the two parallel circles on the celestial sphere having the same latitudes and names as the corresponding lines on the earth

---

adjective

1. a less common word for tropical

tropic Scientific  

/ trŏp′ĭk /

1. Either of the two parallels of latitude representing the points farthest north and south at which the Sun can shine directly overhead. The northern tropic is the Tropic of Cancer and the southern one is the Tropic of Capricorn.

2. tropics. The region of the Earth lying between these latitudes. The tropics are generally the warmest and most humid region of the Earth.

3. Also called Torrid Zone

---

Usage

What does -tropic mean? The combining form -tropic is used like a suffix for a variety of meanings. It can indicate “turned toward, with an orientation toward” something specified by the first part of the word. This sense of -tropic is especially used in biology and botany.It can also denote “having an affinity for, affecting” a specified thing or “affecting the activity of, maintaining” an organ. Here, it can be synonymous with -trophic, which you can learn more about at our Words That Use article for the form. This sense of -tropic is especially used in biochemistry and physiology.Closely related to -tropic is -tropous. The combining forms -tropy and -tropism are used to form abstract nouns from concrete nouns using -tropous and -tropic (and vice versa).Where does -tropic come from?The form -tropic comes from the Greek suffix -tropos, meaning “pertaining to a turn." This suffix is based on trópos, “turn," and tropḗ, "a turning.”The Greek trópos is also the source of trope, tropical, and yes, the word tropic itself. It’s your turn to make the connection between “turning,” figures of speech, and the tropics at our entries for the words.Corresponding forms of -tropic combined to the beginning of words are tropo- and trop-. Discover their specific applications of our Words That Use articles for the forms.

Other Word Forms

• nontropic adjective
• untropic adjective

Etymology

Origin of tropic¹

1350–1400; Middle English < Latin tropicus < Greek tropikós pertaining to a turn, equivalent to tróp ( os ) turn + -ikos -ic

Origin of -tropic²

tropic

Example Sentences

The flooding was caused by an atmospheric river, or a long, narrow stream of moist air in the atmosphere, that traveled to Western Washington and dumped warm, tropic rain across the region.

From Seattle Times • Dec. 7, 2023

The country boasts having the highest number of hummingbirds and bats, attributed to its tropic climate and proximity to the equator.

From Science Daily • Nov. 27, 2023

The engine that powers every tropic cyclone is convection: enormous volumes of moist, rising air create a vacuum at the surface that sucks in surrounding air as spiraling winds.

From Scientific American • Jun. 1, 2023

Floods in Fiji caused by tropic cyclones have displaced thousands of people in recent years and wrought economic havoc.

From BBC • Jun. 12, 2022

Her white skirts swirled around her, bright in the tropic sun.

From "Ship Breaker" by Paolo Bacigalupi