nap‧py S3 plural nappies [countable] British English
a piece of soft cloth or paper worn by a baby between its legs and fastened around its waist to hold its liquid and solid waste [= diaper American English]
Excuse me while I change the baby's nappy.
disposable nappies (=nappies which are made to be used once and thrown away)
nappy rash (=sore skin caused by wet nappies)