Heater

n. heating agent, device which produces heat

A heater is any object that emits heat or causes another body to achieve a higher temperature. In a household or domestic setting, heaters are commonly used to generate heating (ie. warmth).In electronics, the term may refer to the filament in a vacuum tube that heats the cathode to aid in thermionic emission of electrons.
See more at Wikipedia.org...

Noun
1. device that heats water or supplies warmth to a room
(synonym) warmer
(hypernym) device
(hyponym) brazier, brasier
(derivation) heat
2. (baseball) a pitch thrown with maximum velocity; "he swung late on the fastball"; "he showed batters nothing but smoke"
(synonym) fastball, smoke, hummer, bullet
(hypernym) pitch, delivery
(hyponym) slider
(classification) baseball, baseball game, ball

(n.)
One who, or that which, heats.
  

(n.)
Any contrivance or implement, as a furnace, stove, or other heated body or vessel, etc., used to impart heat to something, or to contain something to be heated.
  

The common form of knightly shield introduced from the late 13th century and used commonly all during the 14th century. During the second and third quarter of the century it seems fashionable for knights to carry very small shields, as the examples from existing brassesChronique: The Journal of Chivalry #8