Wordnet 3.0
NOUN (1)
1. 
 (Greek mythology) the daughter of Clytemnestra and Agamemnon; 
 Agamemnon was obliged to offer her as a sacrifice to Artemis when the Greek fleet was becalmed on its way to Troy; 
 Artemis rescued her and she later became a priestess; 
WordNet (r) 3.0 (2006):
Iphigenia
    n 1: (Greek mythology) the daughter of Clytemnestra and
         Agamemnon; Agamemnon was obliged to offer her as a
         sacrifice to Artemis when the Greek fleet was becalmed on
         its way to Troy; Artemis rescued her and she later became a
         priestess