noun
or x-ray source
Usage: usually capitalized X
: a luminous starlike celestial object emitting a major portion of its radiation in the form of X rays
noun
or x-ray source
Usage: usually capitalized X
: a luminous starlike celestial object emitting a major portion of its radiation in the form of X rays
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012