The pesticides caused the male frogs in the nearby pond to become feminized.

feminized 是动词 feminize 的过去分词形式。feminize 由词根 femin-（表示"女性"）和后缀 -ize（表示"使...化"）组成，意思是"使具有女性特征"或"使雌性化"。在句中表示雄性青蛙被改变了性别特征，呈现出雌性特征。