Sindarin 

amlaith

masculine name. Amlaith

1st king of Arthedain (LotR/1038). The meaning of this name is unclear, but its initial element might be am “up”.

Elements

WordGloss
am“up, up, [G.] upwards, towards head of, above”
?
Sindarin [LotRI/Amlaith; PMI/Amlaith] Group: Eldamo. Published by