柯林斯詞典letter bomb (letter bombs) 1. N-COUNT A letter bomb is a small bomb which is disguised as a letter or package and sent to someone through the mail. It is designed to explode when it is opened. 書信(或郵包)炸彈 返回 letter bomb劍橋詞典a small bomb that is put in an envelope or parcel and posted to someone 郵件炸彈 返回 letter bomb