a small piece of table linen that is used to wipe the mouth and to cover the lap in order to protect clothing
"She quickly dabbed her lips with a napkin before covering her lap to keep her dress clean from the soup."
A serviette; a (usually rectangular) piece of cloth or paper used at the table for wiping the mouth and hands for cleanliness while eating.
"He quickly grabbed a napkin to wipe his fingers after breaking off a piece of crusty bread."