These stamps don't adhere well and won't stick firmly to the envelope.

adhere 是动词，由前缀 ad-（表示"朝向"）和词根 here（来自拉丁语 haerere，意为"粘着"）组成，字面意思是"粘附、附着"。在句中指邮票"粘附"在信封上的动作。