existing only in the mind and not real
fictitious, invented
Cases of word usage
1) an imaginary line around which a turning object spins (axis)
2) an imaginary line between areas, countries, surfaces etc (boundary)
3) (the region near) an imaginary line around the Earth, or drawn on maps, at an equal distance from the north and south poles (equator)
4) a small imaginary being with supernatural powers, able to help or harm human beings (fairy)
5) (either half of) an imaginary line round the earth, passing through the north and south poles, as used on maps (meridian)
6) a person, animal or thing of extraordinary or strange size, shape etc; (in stories) a strange, usually frightening, imaginary creature (monster)
7) strange; new; of a kind not previously known; a story in prose, long enough to fill one or more volumes, about either imaginary of historical people (novel)