"Incidentally, 'Port Out Starboard Home': not true."

From A Dictionary of Slang and Cant Barrere and Leland 1890
Jim Carroll

Posh (society), modern term for money, originally used for a halfpenny of small coin, From the gypsy pash or posh, a half. In Romany poshero, the affix ero being corrupted from haro, copper, i.e., a copper or a penny. Posh an' posh, half and half, applied to those who are of mixed blood, or half gypsy. Also a dandy.