pleat
noun
[ pliːt ]
• a double or multiple fold in a garment or other item made of cloth, held by stitching the top or side.
pleat
verb
• fold into pleats.
• "she was absently pleating her skirt between her fingers"
Origin:
late Middle English: a variant of plait. The written form of the word became obsolete between c. 1700 and the end of the 19th century.