Synonyms for Unattended (same or very similar meaning)
WordNet sense 1 (not supervised or under constant observation):
unsupervisedWordNet sense 2 (without accompaniment or companions):
unaccompaniedWordNet sense 3 (lacking a caretaker):
neglectedWordNet sense 4 (lacking needed care and attention):
uncared-forFrom the ODE community, based on WordNetadd/edit