lanthanum
[ lan-thuh-nuh m ]
/ ˈlæn θə nəm /
noun Chemistry.
a rare-earth, trivalent, metallic element, allied to aluminum, found in certain minerals, as monazite. Symbol: La; atomic weight: 138.91; atomic number: 57; specific gravity: 6.15 at 20°C.
Origin of lanthanum
< New Latin (1841), equivalent to
lanthan- (< Greek
lanthánein to escape notice; referring to its position on the periodic table) +
-um, variant of
-ium
-ium
Words nearby lanthanum
lantern-jawed,
lanternfish,
lanternfly,
lanthanide,
lanthanide series,
lanthanum,
lanthorn,
lantsang,
lanuginose,
lanuginous,
lanugo
Example sentences from the Web for lanthanum
British Dictionary definitions for lanthanum
lanthanum
/ (ˈlænθənəm) /
noun
a silvery-white ductile metallic element of the lanthanide series, occurring principally in bastnaesite and monazite: used in pyrophoric alloys, electronic devices, and in glass manufacture. Symbol: La; atomic no: 57; atomic wt: 138.9055; valency: 3; relative density: 6.145; melting pt: 918°C; boiling pt: 3464°C
Word Origin for lanthanum
C19: New Latin, from Greek
lanthanein to lie unseen
Medical definitions for lanthanum
lanthanum
[ lăn′thə-nəm ]
n. Symbol La
A soft malleable metallic rare-earth element used in glass manufacture. Atomic number 57.
Scientific definitions for lanthanum
lanthanum
[ lăn′thə-nəm ]
La
A soft, malleable, silvery-white metallic element of the lanthanide series. It is used to make glass for lenses and lights for movie and television studios. Atomic number 57; atomic weight 138.91; melting point 920°C; boiling point 3,469°C; specific gravity 5.98 to 6.186; valence 3. See Periodic Table.