thermostat vs pyrostat

thermostat and pyrostat both are nouns.

Word	Noun	Adjective	Verb	Adverb
thermostat	Yes	No	Yes	No
pyrostat	Yes	No	No	No

As nouns, pyrostat is a hyponym of thermostat; that is, pyrostat is a word with a more specific, narrower meaning than thermostat:

thermostat: a regulator for automatically regulating temperature by starting or stopping the supply of heat
pyrostat: a thermostat that operates at very high temperatures

Other hyponyms of thermostat include cryostat.

thermostat (noun)	pyrostat (noun)
a regulator for automatically regulating temperature by starting or stopping the supply of heat	a thermostat that operates at very high temperatures

thermostat (verb)	pyrostat (verb)
control the temperature with a thermostat