Wordnet 3.0
ADJECTIVE (2)
1. 
 characteristic of pirates; 
- Example: "piratical attackers"2. 
 characteristic of piracy; 
- Example: "piratical editions of my book"
The Collaborative International Dictionary of English v.0.48:
Piratical \Pi*rat"ic*al\, a. [L. piraticus, Gr. ?: cf. F.
   piratique.]
   Of or pertaining to a pirate; acquired by, or practicing,
   piracy; as, a piratical undertaking. "Piratical printers."
   --Pope. -- Pi*rat"ic*al*ly, adv.
   [1913 Webster]
WordNet (r) 3.0 (2006):
piratical
    adj 1: characteristic of pirates; "piratical attackers"
    2: characteristic of piracy; "piratical editions of my book"