-kshən noun
( -s )
Etymology: Late Latin convection-, convectio, from Latin convectus (past participle of convehere to bring together, from com- + vehere to carry) + -ion-, -io -ion — more at way
1. : the action or process of conveying or transmitting
2. : a mechanically or thermally produced upward or downward movement of a limited part of the atmosphere that is essential to the formation of many clouds (as cumulus clouds) and is used in certain heating systems
3.
a. : the circulatory motion that occurs in a fluid at a nonuniform temperature owing to the variation of its density and the action of gravity
b. : the transfer of heat by this automatic circulation of a fluid — compare conduction 5a
c. : the transfer of electricity in the form of a surface charge on a moving body (as an electrostatic-generator belt)