As a proper noun alan
is or alan
can be (historical) a member of a group of sarmatian tribes, nomadic pastoralists of the 1st millennium ad who spoke an eastern iranian language derived from scytho-sarmatian and which in turn evolved into modern ossetian.
As a noun alane is
Other Comparisons: What's the difference?
(inorganic compound) aluminium hydride, AlH3
(organic chemistry) Any organic derivative of this compound
This is the current IUPAC name, but is to be replaced by alumane because the systematically derived name of the -AlH2 group would be alanyl which is already used as a derivative of alanine.