The queen announced she would abdicate due to health reasons.

abdicate 是动词，由前缀 ab-（表示"离开"）和词根 dic（表示"说、宣布"）加上动词后缀 -ate 组成，字面意思是"宣布离开"，引申为"放弃（王位、权力等）"或"退位"。