'Search the wordnet for this word, based on user options.
:return: A list of related words.'

def _search_wn(self, word):

    result = []
    if ((not word) or word.isdigit()):
        return result
    with self._plugin_lock:
        try:
            result.extend(wn.synsets(word)[0].hypernyms()[0].hyponyms())
        except:
            pass
        synset_list = wn.synsets(word)
        for synset in synset_list:
            result.append(synset)
            result.extend(synset.hypernyms())
            result.extend(synset.hyponyms())
            result.extend(synset.member_holonyms())
            result.extend(synset.lemmas()[0].antonyms())
    result = [i.name().split('.')[0] for i in result]
    result = [i.replace('_', '    ') for i in result]
    result = list(set(result))
    if (word in result):
        result.remove(word)
    result = self._popularity_contest(result)
    result = result[:self._wordnet_results]
    return result
