Eyewitness

Vine's Expository Dictionary of NT Words

1: αὐτόπτης (Strong'S #845 — Noun Masculine — autoptes — ow-top'-tace )

signifies "seeing with one's own eyes" (autos, "self," and a form, optano, "to see"),  Luke 1:2 .

2: ἐπόπτης (Strong'S #2030 — Noun Masculine — epoptes — ep-op'-tace )

primarily "an overseer" (epi, "over"), then, a "spectator, an eye-witness" of anything, is used in  2 Peter 1:16 of those who were present at the transfiguration of Christ. Among the Greeks the word was used of those who had attained to the third grade, the highest, of the Eleusinian mysteries, a religious cult at Eleusis, with its worship, rites, festival and pilgrimages; this brotherhood was open to all Greeks. In the Sept.,   Esther 5:1 , where it is used of God as the Overseer and Preserver of all things. Cp. epopteuo, "to behold,"  1 Peter 2:12;  3:2 .

Webster's Dictionary

(n.) One who sees a thing done; one who has ocular view of anything.