4 occurrences in 4 dictionaries
Reference: Barkos
Hastings
Ancestor of certain Nethinim who returned with Zerubbabel (Ezr 2:53; Ne 7:55; called Barchus in 1Es 5:32).
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Smith
Bar'kos
(painted). "Children of Barkos" were among the Nethinim who returned from the captivity with Zerubbabel.
(B.C. 536.)