The proposal to change the rules was narrowly defeated by 201 votes to 196.

defeated 是动词 defeat 的过去分词形式，在句中表示被动。defeat 由前缀 de-（表示"去除、否定"）和词根 feat（来自拉丁语 factum，意为"完成、成就"）组成，字面意思是"使成就无效"，即"击败、否决"的意思。defeated 在这里表示"被否决"的状态。