astronomical horizon
noun
The horizon that would be seen if the earth's surface were perfectly smooth; the intersection of a horizontal plane through an observer with the celestial sphere.
Origin
Mid 18th century; earliest use found in Temple Henry Croker (1729–?1790), writer.
- insolvent
- in so many words
- in someone's bad (or good) books
- in someone's black books
- in someone's confidence
- in someone's corner
- in someone's hip pocket
- in someone's keeping
- in someone's lap
- in someone's name
- in someone's place
- in someone's pocket
- in someone's wisdom
- in someone/thing's (own) way
- in some sort
- insomnia
- insomniac
- insomuch
- in sooth
- insouciance
- insouciant
- insouciantly
- insource
- insourcing
- insp.