1911, from German Allergie, coined 1906 by Austrian pediatrician Clemens E. von Pirquet (1874-1929) as an abstract noun from Greek allos "other, different, strange" (from PIE root *al- (1) "beyond") + ergon "activity," from PIE root *werg- "to do."
allemande
Allen
allergen
allergic
allergist
allergy
alleviate
alleviation
alley
alleyway
all-fired