Complex sentence: In Polish a common formal term to describe an Englishman is "Anglik", derived from the Polish word for England, "Anglia", with the word "Brytyjczyk" meaning Briton, from the Polish name for Great Britain, "Wielka Brytania".
Split into simpler sentences: In Polish a common formal term to describe an Englishman is "Anglik", or "Brytyjczyk" for a British. The first one is derived from the Polish word for England "Anglia", the latter from a Polish word for Great Britain "Wielka Brytania".