(especially in medieval castles) a strong grating, as of iron, made to slide along vertical grooves at the sides of a gateway of a fortified place and let down to prevent passage.
Origin: 1300–50;Middle Englishportecolys < Middle Frenchporte coleice, equivalent to porteport4 + coleice, feminine of coleis flowing, sliding < Vulgar Latin*cōlātīcius; see coulee, -itious
an iron or wooden grating suspended vertically in grooves in the gateway of a castle or fortified town and able to be lowered so as to bar the entrance
[C14 port colice, from Old French porte coleïce sliding gate, from porte door, entrance + coleïce, from couler to slide, flow, from Late Latin cōlāre to filter]
c.1300, from O.Fr. porte coleice "sliding gate" (c.1200), from porte "gate" (see port (2)) + coleice "sliding, flowing," fem. of coleis, from L. colatus, pp. of colare "to filter, strain."