a small piece of thick rough material which covers part of a floor:
Wipe your feet on the mat.
a small flat piece of wood, cloth etc which protects a surface, especially on a table: ➔ place mat
a beer mat (=a mat for putting a glass of beer on)
a mouse mat (=for a computer mouse)
a piece of thick soft material used in some activities for people to sit on, fall onto etc:
a yoga mat
a prayer mat
to do everything you can to solve a difficult problem, win an argument, support someone etc:
The mayor is willing to go to the mat on this issue.
a thick mass of something such as hairs or leaves [↪ matted]
a floating mat of vegetation