Wordnet 3.0
NOUN (1)
1. 
 a pen for swine; 
[syn: sty, pigsty, pigpen]
The Collaborative International Dictionary of English v.0.48:
Pigsty \Pig"sty`\, n.; pl. Pigsties.
   A pigpen.
   [1913 Webster]
WordNet (r) 3.0 (2006):
pigsty
    n 1: a pen for swine [syn: sty, pigsty, pigpen]