What does "orgue" mean?

Orgue: (a) Any one of a number of long, thick pieces of timber, pointed and shod with iron, and suspended, each by a separate rope, over a gateway, to be let down in case of attack. (b) A piece of ordnance, consisting of a number of musket barrels arranged so that a match or train may connect with all their touchholes, and a discharge be secured almost or quite simultaneously.