The political system of this small country is essentially oligarchical, controlled by a handful of wealthy families.

oligarchical 是形容词，由名词 oligarchy（寡头政治）加上形容词后缀 -ical 构成。oligarchy 来自希腊语 oligos（少数的）和 arkhein（统治），字面意思是"少数人统治"。oligarchical 表示"寡头政治的、少数人掌控的"。