Sindarin 

ethring

place name. *Across Cold

Name of a bridge across the river Ringló appearing on the maps of The Lord of the Rings (LotR/1086). The second element of this name is almost certainly ring “cold”. This first element may be a mutated form of the prefix [N.] ath- “across”, with [[s|short [a] becoming [e] preceding an [i]]] (as suggested by David Salo, GS/378).

Elements

WordGloss
ath-“on both sides, across”
ring“cold, chill, cold, chill, [G.] cool”