"Alleviate" is usually used when it comes to symptoms of illness. Example: "This medication will alleviate your bad cough." "Allay" is usually used with respect to fears or worries. Example: "This study guide will allay your worries about the upcoming exam."

What does it mean to alleviate something?

transitive verb. : relieve, lessen: such as. a : to make (something, such as pain or suffering) more bearable a drug that alleviates the symptoms using relaxation techniques to alleviate stress To draw customers, [Richard G.]

What does allay them mean?

transitive verb. 1 : to subdue or reduce in intensity or severity : alleviate expect a breeze to allay the heat. 2 : to make quiet : calm trying to allay their fears.