Mammoth Uncensored Word List:
27 words ending with y, 21 letters long

acrocephalosyndactyly antiferromagnetically astrophotographically chemolithotrophically cholecystogastrostomy cholecystojejunostomy cholecystolithotripsy cholecystonephrostomy clinicopathologically dacryocystorhinostomy dendrochronologically electrochromatography electromyographically glottochronologically intersubstitutability mechanotheraputically microradiographically nonstereospecifically overimpressionability photolithographically posttranscriptionally psychoimmunologically psychoneuroimmunology psychophysiologically psychotherapeutically sphygmomanometrically stereomicroscopically