Quidam

Qui'dam noun [ Latin ] Somebody; one unknown. Spenser.
Found on http://www.encyclo.co.uk/webster/Q/10

Quidam

• (n.) Somebody; one unknown.
Found on http://thinkexist.com/dictionary/meaning/quidam/

quidam

a certain person; somebody
Found on http://phrontistery.info/q.html
No exact match found