'A set of synonyms that share a common meaning.'

def __init__(self, synset=None, pos=NOUN):

    if isinstance(synset, int):
        synset = wn.getSynset({NN: 'n', VB: 'v', JJ: 'adj', RB: 'adv'}[pos], synset)
    if isinstance(synset, basestring):
        synset = synsets(synset, pos)[0]._synset
    self._synset = synset
