The act of striking one's flaccid penis against their own lower abdomen, in order to create a resonating 'clonking' sound.

It is absolutely essential that the penis is flaccid. The softer the penis, the louder and deeper the 'clonk'.

Having lots of excess foreskin can also have an advantage as it adds a 'whipping' noise to the 'clonk'.

If the tip of the flaccid penis can reach the naval, then it creates a beautiful, deep 'bonk' sound.
Once the slap up has been fully mastered, the 'clonk', 'whip' and 'bonk' sounds can all be heard with one well timed crack of the penis.
Some slap up's can be heard for miles around, and is said to be part of a mating call used by people in certain parts of the world.
Once again it is essential that the penis is flaccid. Striking a hard penis against the lower abdomen can cause the penis blood vessels to burst, bruising, internal bleeding, and even death.

To give, to share something with someone.

Slap up

adjective BRITISH informal
(of a meal or celebration) large and sumptuous. First rate.

The act of hitting or slapping someone abrubtly, for saying something foolish.

Verb:

1) the way of describing a senior member of staff negatively critiquing a piece of work, even though effort or partial effort was put onto it.
2) the way of a member of management unjustifiably “destroying” / “going-to-town” on a piece of work in front of colleagues to make them feel superior.

In both examples this leaves you deflated and wondering why you bothered. A few hours of job searching usually ensues.

Not to be confused with ‘bussing’ where a similar level colleague purposely discredits your work due to lack of effort on their part so it gets ‘slapped up’ to draw attention away from them.
"Stephen just threw me under the bus"

An event where non people, i.e artists and transgender folk, gather to strip naked and slap each others bodies whilst wearing false nails. Towards the end of the event, the tide turns from innocent naked slapping into an intense sexual affair where the slap of pelvic thrust against chafed buttocks gives it the name 'Briggsy Slap Up'

1) to be completely burnt.

2) In the case of mechanical repairs it can refer to a busted engine, compressor, or motor.

1) A very cheap, and fatty, meal.
2) A takeaway from your local 'cafe'.

Phrase used to express enthusiastic endorsement of an idea, particularly if the idea pertains to the recent or imminent acquisition of goods or information. While some believe the term descends from "sop it up with a biscuit" or the practice of slapping someone upside the head, "slap it up" most likely refers to the literal action of placing a desired object on a surface with considerable force, as a means of presentational flourish.