noun. a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime.
1. Noun, singular or mass The gauges are designed for specific coolants to give you an accurate reading, so if your system does have FREON(tm) refridgerent, the gauges should be designed for that.