rail
‘a bar of timber or metal; a bar extending horizontally between supports; a railing’
Lexical development traced from the Tamil root:
E. ryle, raylle, rale, rall < O.F. raille, reille ‘bolt, bar’ < Vulgar Lat. regla < Lat. regula ‘rule, straight piece of wood’ < regere ‘to straighten, guide’ < ray < reg- < Tamil aracaṉ