Short definition
A wine flaw caused by a chemical compound (TCA) in the cork that makes wine smell like wet cardboard or a damp basement.
A corked wine has been contaminated by TCA (2,4,6-trichloroanisole), a compound that forms when natural fungi in cork meet certain cleaning chemicals. It mutes fruit aromas and replaces them with the smell of wet newspaper, musty basement, or soggy cardboard. A slightly corked wine just tastes flat and dull. A badly corked wine is unmistakable. It is not harmful — just unpleasant. Send it back at a restaurant without hesitation.