a steam engine; an external combustion engine that performs mechanical work using steam as its working fluid; short for 蒸汽机 zhēng​qì​jī

a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft; short for 汽轮机 qì​lún​jī or 蒸汽轮机 zhēng​qì​lún​jī