According to the search results, "knotting" has multiple meanings on Urban Dictionary. It can refer to:

• Being fully penetrated by a canine penis, including the bulbous knot near the base, causing the two creatures to be locked together until the male can ejaculate.
• A tangled mass of hair that is created in the area between your anus and scrotum due to poor wiping, sweat, hygiene, and/or rigorous physical activity.
• A sexual move performed orally when two fingers are placed in the pussy. One on the clit, the other halfway in the hole, while the tongue is used to lick.
• An item which prevents an individual from wearing skinny jeans.
• A phrase meaning "get fucked" but nice.
• In bestiality, the act of being completely penetrated vaginally, orally, or anally by an animal such as a dog.

It is important to note that Urban Dictionary is a crowdsourced website where users can submit their own definitions, and the content may not always be reliable or appropriate.