Powszechna Kasa Oszczędności Bank Polski Spółka Akcyjna is Poland's largest bank founded in 1919. Peacekeeping Operation (various organizations) PKO. Looking for the definition of PKO? Find out what is the full meaning of PKO on Abbreviations. Palm kernel oil (PKO) contains primarily trigylcerides with short chain fatty acids. What does PKO mean? This page is all about the meaning, abbreviation and acronym of PKO explaining the definition or meaning and giving useful information of.