Wordnet 3.0
NOUN (1)
1. 
 a battle between the successors of Alexander the Great (301 BC); 
 Lysimachus and Seleucus defeated Antigonus and Demetrius; 
[syn: Ipsus, battle of Ipsus]
The Collaborative International Dictionary of English v.0.48:
Ipsus \Ipsus\ prop. n.
   a battle between the successors of Alexander the Great (301
   BC); Lysimachus and Seleucus defeated Antigonus and
   Demetrius.
   Syn: battle of Ipsus.
        [WordNet 1.5] IQ
WordNet (r) 3.0 (2006):
Ipsus
    n 1: a battle between the successors of Alexander the Great (301
         BC); Lysimachus and Seleucus defeated Antigonus and
         Demetrius [syn: Ipsus, battle of Ipsus]