asperity /a-sperˈi-ti/

1. Roughness
2. Harshness
3. Bitter coldness
4. (in pl) excrescences, rough places

• knock for six
• knocking
• knocking copies
• knocking copy
• knockings
• knocking shop
• knocking-shop
• knocking shops
• knocking-shops
• knock into a cocked hat
• knock into the middle of next week
• knock-knee
• knock-kneed
• knock-knees
• knock off
• knock on
• knock-on
• knock-on effect
• knock one's head against a brick wall
• knock on the head
• knock on wood
• knock out
• knockout
• knockout auction
• knockout auctions