An allergic response is a reaction of the body's immune system to a foreign substance, such as pollen or dust. This reaction can be manifested in a variety of ways, including sneezing and watery eyes. The two crossword solutions for the term 'allergic response' are ACHOO (5 letters) and SNEEZE (6 letters). ACHOO is an onomatopoeia that is used to describe the sound of a sneeze, while SNEEZE is the action of expelling air from the nose and mouth in order to expel irritants.