The term 'extraterrestrial' refers to any life form that exists outside of Earth. The crossword solutions for this term are 'EERIE' (5 letters), 'ALIEN' (5 letters), 'fatherplanet' (11 letters), and 'inhumanbeing' (12 letters). These words all describe something that is not from Earth, and can be used to refer to extraterrestrial life forms. 'EERIE' implies a feeling of unease or fear, while 'ALIEN' is a more general term for something that is not from Earth. 'Fatherplanet' suggests a planet that is the origin of an extraterrestrial species, and 'inhumanbeing' implies a creature that is not human.