W. H. Grattan Flood in the context of "Uilleann pipes"

The uilleann pipes (/ˈɪlən/ IL-ən or /ˈɪljən/ IL-yən, Irish: [ˈɪl̠ʲən̪ˠ]), also known as Union pipes and sometimes called Irish pipes, are the characteristic national bagpipe of Ireland. Their current name is a partial translation of the Irish language terms píobaí uilleann (literally, "pipes of the elbow"), from their method of inflation. There is no historical record of the name or use of the term uilleann pipes before the 20th century. The name was an invention of Grattan Flood and it stuck. People mistook the term "union" to refer to the 1800 Act of Union; however, this is incorrect as Breandán Breathnach points out that a poem published in 1796 uses the term "union".

The bag of the uilleann pipes is inflated by means of a small set of bellows strapped around the waist and the right arm (in the case of a right-handed player; in the case of a left-handed player the location and orientation of all components are reversed). The bellows not only relieve the player from the effort needed to blow into a bag to maintain pressure, they also allow relatively dry air to power the reeds, reducing the adverse effects of moisture on tuning and longevity. Some pipers can converse or sing while playing. The bag which the bellows fill is clamped under the other elbow, which squeezes the bag to control the flow of air to the reeds (which make the notes).