Wordnet 3.0
NOUN (1)
1. 
 Chinese philosopher regarded as the founder of Taoism (6th century BC); 
[syn: Lao-tzu, Lao-tse, Lao-zi]
WordNet (r) 3.0 (2006):
Lao-tzu
    n 1: Chinese philosopher regarded as the founder of Taoism (6th
         century BC) [syn: Lao-tzu, Lao-tse, Lao-zi]