The term 'alien craft' often refers to unidentified flying objects or UFOs. In the field of ufology, there are several synonyms used for describing those unidentified flying objects. One of the frequently used synonyms is 'flying saucers,' which evokes the shape most commonly associated with UFO sightings. Another popular term is 'unidentified aerial phenomenon' or UAP, which is a more scientific term coined by the U.S. military. Other synonyms for alien crafts include 'flying discs,' 'extraterrestrial vehicles,' 'mystery objects,' and 'strange flying vehicles.' These various terms help create a better understanding of potential encounters with unidentified flying objects.