tropic

• trop. (abbreviation)
• tropick (obsolete)
• Tropic

From Late Latin tropicus (“of or pertaining to the solstice, as a noun, one of the tropics”), from Ancient Greek τροπικός (tropikós, “of or pertaining to a turn or change; or the solstice; or a trope or figure; tropic; tropical; etc.”), from τροπή (tropḗ, “turn; solstice; trope”).

• Rhymes: -ɒpɪk

tropic (plural tropics)

1. either of the two parallels of latitude 23°27′ north and south of the equator; the farthest points at which the sun can be directly overhead; the boundaries of the torrid zone or tropics
   • 1645, James Howell, “England’s Tears, for the Present Wars, which for the Nature of the Quarrel, the Quality of the Strength, the Diversity of Battels, Skirmishes, Encounters, and Sieges, (Happened in so Short a Compasse of Time) Cannot be Parallel’d in Any Precedent Age”, in ΔΕΝΔΡΟΛΟΓΊΑ [DENDROLOGIA]: Dodona’s Grove, or The Vocall Forrest. The Third Edition More Exact and Perfect than the Former; with the Addition of Two Other Tracts: viz. Englands Tears for the Present Wars. And The Pre-eminence of Parlements, 3rd edition, Cambridge: Printed by R. D. for Humphrey Moseley, and are to be sold at his shop at the Prince's Arms in S. Pauls Church-yard, OCLC 931321630, page 189:

     O conſider my caſe, moſt blisfull Queen, […] Diſpell thoſe Clouds which hover 'twixt my King and his higheſt Counſell, […] that my great Law-making Court be forced to turn no more to polemicall Committees, […] but that they may come again to the old Parliamentary Rode, To the path of their Predeceſſours, to conſult of means how to ſweep away thoſe Cobwebs that hang in the Courts of Juſtice, and to make the Laws run in their right Channell; to retrench exceſſive fees, and finde remedies for the future, that the poor Client be not ſo peeled by his Lawyer, and made to ſuffer by ſuch monſtrous delays, that one may go from one Tropick to the other, and croſſe the Equinoctiall twenty times, before his ſute be done; […]

tropic (comparative more tropic, superlative most tropic)

1. Of, or relating to the tropics; tropical.
2. (weather, climate) hot and humid.
3. (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.

In chemical sense, not to be confused with similar-sounding trophic – the words and concepts are unrelated.[1]

• tropic in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.
• tropic in The Century Dictionary, New York, N.Y.: The Century Co., 1911.
• tropic at OneLook Dictionary Search

• Pictor, protic