Lanthanides

The lanthanide (or lanthanoid) series comprises the 15 elements with atomic numbers 57 through 71, from lanthanum to lutetium. All lanthanides are f-block elements, corresponding to the filling of the 4f electron shell, except for lutetium which is a d-block lanthanide. The lanthanide series is named after lanthanum.
See more at Wikipedia.org...

Noun
1. any element of the lanthanide series (atomic numbers 57 through 71)
(synonym) rare earth, rare-earth element, lanthanoid, lanthanon
(hypernym) group, grouping
(hyponym) terbium metal

n. lanthanide

La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb

LANTANIDI