'Oik' is a derogatory piece of British slang meaning 'common
' or 'uneducated
' - the direct American equivalent would be 'okie
', and like that word it is somewhat out-of-date nowadays.
Whereas 'okie' refers to presumed natives of 'Oklahoma', 'oik' most likely derives from the way that Geordies (such as the actor Timothy Spall) pronounce '-ike' as '-oik'.
It is also the acronym for the European property investment company 'Oppenheim Immobilien-Kapitalanlagegesellschaft mbH'.
'Oik' will score you at least five points in a game of Scrabble, whilst 'Kapitalanlagegesellschaft' will score you lots of points if you have a large enough board.