: a layer of material that is placed under something else (such as a carpet)
What made you want to look up underlay? Please tell us where you read or heard it (including the quote, if possible).
Take Our 10-Question Quiz
Take our visual vocab quiz
A quick quiz about stuff worth knowing
The commonly misspelled words quiz
The Vocab Quiz Game for iPhone & iPad
"Incredibly fun and addictive. And informative!" User Review, iTunes