al ‧ ler ‧ gy /ˈælədʒi $ -ər-/ BrE AmE noun ( plural allergies ) [uncountable and countable]
[ Date: 1900-2000 ; Language: German ; Origin: allergie , from all- 'all' + Greek ergon 'work' ]
a medical condition in which you become ill or in which your skin becomes red and painful because you have eaten or touched a particular substance
allergy to
I have an allergy to cats.
a food allergy