1. The act or process of conveying; transmission.
a. Heat transfer in a gas or liquid by the circulation of currents from one region to another.
b. Fluid motion caused by an external force such as gravity.
3. Meteorology The transfer of heat or other atmospheric properties by massive motion within the atmosphere, especially by such motion directed upward.
[Late Latinconvectiō, convectiōn-, fromconvectus, past participle ofconvehere, to carry together : Latincom-, com- + Latinvehere, to carry; see wegh- in the Appendix of Indo-European roots.]
(click for a larger image)convection
Air heated by a space heater rises and is replaced by cool air, creating a convection current that circulates hot air throughout a room.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.