quidam

Quidam (pronounced "key-DAHM"; ) means "a certain one/thing" or "anonymous passerby" in Classical Latin, and is the ninth show produced and performed by Cirque du Soleil. The entire show is imagined by a young girl, named Zoe, a sad and forlorn girl who is alienated and ignored by her parents. She dreams up the whimsical world of Quidam in an attempt to escape her sadness.The title refers to the feature character, best described as a giant Headless Horseman sans horse, carrying an umbrella and a bowler hat. Quidam is said to be the embodiment of both everyone and no one at the same time. Subtitles at the beginning of the official video state: Quidam: a nameless passer-by, a solitary figure lingering on a street corner, a person rushing past. One who cries out, sings and dreams within us all.
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n. fellow, guy, chap

n. a certain person

n. somebody, some person, unspecified person; nobody, no person; unimportant person (Slang)

nobody, unimportant person, no person