thulium

[ thoo-lee-uh m ]
/ ˈθu li əm /

noun Chemistry.

a rare-earth metallic element found in the minerals euxenite, gadolinite, etc. Symbol: Tm; atomic weight: 168.934; atomic number: 69; specific gravity: 9.32.

Origin of thulium

From New Latin, dating back to 1875–80; see origin at Thule, -ium

British Dictionary definitions for thulium

thulium
/ (ˈθjuːlɪəm) /

noun

a malleable ductile silvery-grey element occurring principally in monazite. The radioisotope thulium-170 is used as an electron source in portable X-ray units. Symbol: Tm; atomic no: 69; atomic wt: 168.93421; valency: 3; relative density: 9.321; melting pt: 1545°C; boiling pt: 1950°C

Word Origin for thulium

C19: New Latin, from Thule + -ium

Medical definitions for thulium

thulium
[ thōōlē-əm ]

n. Symbol Tm

A rare-earth element having an x-ray emitting isotope that is used in small portable medical x-ray units. Atomic number 69.

Scientific definitions for thulium

thulium
[ thōōlē-əm ]

Tm

A soft, silver-gray metallic element of the lanthanide series. One of its artificial radioactive isotopes is used as a radiation source in small, portable x-ray machines. Atomic number 69; atomic weight 168.934; melting point 1,545°C; boiling point 1,727°C; specific gravity 9.3; valence 2, 3. See Periodic Table.