visible horizon vs apparent horizon

visible horizon and apparent horizon both are nouns.

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

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

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

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

visible horizon (noun)	apparent horizon (noun)
the line at which the sky and Earth appear to meet	the line at which the sky and Earth appear to meet