The bank's quarterly interest rate was annualized to show 4.5%.

annualized 是动词 annualize 的过去分词形式，由名词 annual（年度的）加上后缀 -ize（使...化）构成，表示"按年度计算"或"换算成年利率"。annualized 在这里指将季度利率换算为等效的年利率。