Preparing a reliable lexical semantic network by experts requires a great investment and a long time. Although there are many computer-based studies for Turkish, there is no reliable and complete semantic network yet. Therefore, in this study, we present a semantic network automatically generated from a Turkish dictionary with a validation method for the reliability of the extracted relations. In this network, synonym relations between word senses are extracted with text patterns, then they are validated by using semantic relations obtained from definition sentences in the dictionary. In order to show its success, the proposed network is compared to one of the literature studies. As a result, this study emphasizes that the reliability of semantic relations is more valuable than the number of relations found.