This Scottish poet rhymed "purple" with "curple" (meaning "the rump")
Beryl: Curple- the hindquarters or the rump of a horse and a strap 
under the girth of a horse's saddle to stop the saddle from kicking forward, hurple- 
a scottish word (still used today actually) which means to hobble or walk with a... [DOC] [TLE] Full text of "A Scot's dialect dictionary, comprising the words in use ... [PAR] This Scottish Dictionary is intended to deal with what should interest all ...