visible horizon vs skyline

visible horizon and skyline both are nouns.

Word	Noun	Adjective	Verb	Adverb
visible horizon	Yes	No	No	No
skyline	Yes	No	No	No

As nouns, visible horizon and skyline are synonyms defined as:

visible horizon and skyline: the line at which the sky and Earth appear to meet

Other synonyms of visible horizon include apparent horizon, horizon, sensible horizon.

visible horizon (noun)	skyline (noun)
the line at which the sky and Earth appear to meet	the line at which the sky and Earth appear to meet
	the outline of objects seen against the sky