allergy

The word “allergy” means a condition in which the immune system overreacts to a normally harmless substance, causing symptoms such as sneezing, rashes, or swelling. In plain terms, an oversensitive immune reaction to something ordinarily harmless, like pollen, nuts, or pet hair.

“Allergy” is pronounced AL-uh-jee ([ˈæl.ɚ.d͡ʒi] in IPA).

Here is “allergy” used in a sentence: “His allergy to pollen gets worse every spring.”

Words with a similar meaning to “allergy” include type 1 hypersensitivity.

“Allergy” is a noun.

The word “allergy” dates back to around 1906 and comes from Greek. Coined in 1906 by the Austrian doctor Clemens von Pirquet, combining Greek allos ("other") and ergon ("work, reaction") to describe the immune system reacting abnormally.

“Allergy” is an uncommon word in modern English.

“Allergy” has 2 distinct senses listed in this dictionary. The most common is: a condition in which the immune system overreacts to a normally harmless substance, causing symptoms such as sneezing, rashes, or swelling.

An allergy involves the immune system overreacting to a normally harmless substance, producing symptoms such as sneezing, rashes, or swelling. An intolerance, by contrast, typically involves the digestive system reacting to a substance without immune system involvement, and is generally less severe.

Yes, "allergy" can be used figuratively to describe a strong dislike or aversion to something, such as "an allergy to paperwork." In this sense, it has nothing to do with the immune system and simply emphasizes intense distaste.

"Allergy to" is the correct and standard preposition, as in "an allergy to peanuts" or "an allergy to pollen." "Allergy of" is not idiomatic English usage.