I. ˈhēd.ə(r), -ētə- noun
( -s )
Etymology: Middle English heter, from heten to heat + -er — more at heat
1. : something that heats : a contrivance that imparts heat or holds something to be heated: as
a. : a stove, furnace, radiator, or other device for giving off heat
b. : an iron core for heating box irons
c. : a wire or filament in an electron tube that heats the cathode indirectly
2.
a. : one whose work is to heat something — often used in combination
rivet heater
tire heater
b. : one that heats metal billets to make them workable
c. : one that tends the burners that heat a petroleum-products still
3. slang : pistol
II. noun
: a baseball pitch that is extremely hard and fast