Building a wordnet from scratch is a huge task, especially for languages less equipped with pre-existing lexical resources such as thesauri or bilingual dictionaries. We address the issue of costliness of human supervision through crowdsourcing that offers a good trade-off between quality of output and speed of progress. In this paper, we demonstrate a two-phase crowdsourcing workflow that consists of a synset localization step followed by a validation step. Validation is performed using the inter-rater agreement metrics Fleiss’ kappa and Krippendorf’s alpha, which allow us to estimate the precision of the result, as well as to set a balance between precision and recall. In our experiment, 947 synsets were localized from English to Mongolian and evaluated through crowdsourcing with the precision of 0.