What is the meaning of Loaf?

(also loaf of bread) A block of bread after baking.

Any solid block of food, such as meat or sugar.

The brain or the head (mainly in the phrase use one's loaf).

A solid block of soap, from which standard bar soap is cut.

A particular still life configuration with seven living cells.

To headbutt

(Can we verify this sense?) To assume or be in catloaf position (for cats or other animals)

To do nothing, to be idle.

Source: wiktionary.org