Knicker/ˈnɪkər/ Definition 1 of 2Pro Tip 1/3Clothing Piece In the UK or Australia, 'knickers' refer to women's undergarments, not men's. She bought a new pair of lace knickers. Pro Tip 2/3Not Shorts 'Knicker' can also mean short pants, but it's not common clothing in the present day. The vintage outfit included classic woolen knickers. Pro Tip 3/3Plural Form The term is mostly used in the plural form, even when referring to one piece. Her new knickers have a floral pattern.