This is possible because language is not the only symbolic means of communication. In order to prove that chimpanzees and gorillas are capable of language, and not simply a different kind of symbolic communication system, they must learn a sign language with the basic characteristics of human language.
Definition of Halloween. : October 31 observed especially with dressing up in disguise, trick-or-treating, and displaying jack-o'-lanterns during the evening.
Samhain. Halloween can be traced back 2,000 years to an Oct. 31 Gaelic festival called Samhain (pronounced sah-win), which means summer's end in Gaelic. The new harvest year was considered to be on Nov. 1.