1. (a.) Of, pertaining to, or designating, an acid obtained from atropine and certain other alkaloids, as a white crystalline substance slightly soluble in water.

2. (n.) One of the two small circles of the celestial sphere, situated on each side of the equator, at a distance of 23 28/, and parallel to it, which the sun just reaches at its greatest declination north or south, and from which it turns again toward the equator, the northern circle being called the Tropic of Cancer, and the southern the Tropic of Capricorn, from the names of the two signs at which they touch the ecliptic.

3. (n.) One of the two parallels of terrestrial latitude corresponding to the celestial tropics, and called by the same names.

4. (n.) The region lying between these parallels of latitude, or near them on either side.

5. (a.) of or pertaining to the tropics; tropical.

Antarctic Zone Arctic Circle Arctic Zone Frigid Zones Torrid Zone Tropic of Cancer Tropic of Capricorn Variable Zones Weltanschauung air ambiance ambience ambient atmosphere aura calm weather climate of opinion clime cold weather equator ethos fair weather feel feeling forces of nature good weather halcyon days horse latitudes hot weather ideology intellectual climate latitude longitude longitude in arc macroclimate medium meridian microclimate milieu mise-en-scene mood moral climate mores norms note overtone parallel prime meridian quality rainy weather roaring forties sense spirit spiritual climate stormy weather subtropics surroundings the elements the line tone tropic tropics undertone weather windiness world view zone