come into sight or view
"He suddenly appeared at the wedding"
"A new star appeared on the horizon"
come into being or existence, or appear on the scene
"Then the computer came along and changed our lives"
"Homo sapiens appeared millions of years ago"
appear as a character on stage or appear in a play, etc.
"Gielgud appears briefly in this movie"
"She appeared in `Hamlet' on the London stage"
present oneself formally, as before a (judicial) authority
"He had to appear in court last month"
"She appeared on several charges of theft"
To come or be in sight; to be in view; to become visible.
"After hours of searching through the dense fog, the lighthouse finally appeared on the horizon."
In plain English: To appear means to become visible or show up in front of someone.
"The sun began to appear over the horizon after the storm passed."
Usage: Use "appear" to describe something becoming visible or coming into view, such as clouds appearing on the horizon. Do not use it to mean "to seem" when describing a quality, as that usage is often confused with its literal sense of physical presence.
The word "appear" entered English from Old French and Latin, where it originally meant "to come forth or become visible." Its roots trace back to a Proto-Indo-European verb meaning "to watch," which also gives us the modern sense of something being seen.