Webster's Revised Unabridged Dictionary · 1913

Croup

Croup (krop) , noun

[French croupe hind quarters, croup, rump, of German or Icelandic origin; compare Icelandic kryppa hump; akin to Icelandic kroppr. Compare Crop.]

The hinder part or buttocks of certain quadrupeds, especially of a horse; hence, the place behind the saddle.
So light to the croup the fair lady he swung, So light to the saddle before her he sprung. — Sir W. Scott

Croup (krop) , noun

[Scot. croup, compare croup, crowp, to croak, to cry or speak with a hoarse voice; compare also LG. kropp, German kropf, the crop or craw of a bird, and tumor on the anterior part of the neck, a wen, etc. Compare Crop.]

(Medicine) An inflammatory affection of the larynx or trachea, accompanied by a hoarse, ringing cough and stridulous, difficult breathing; esp., such an affection when associated with the development of a false membrane in the air passages (also called membranous croup). See False croup, under False, and Diphtheria.