What is the meaning of Tombstoning?

The practice of jumping into the sea or similar body of water from a cliff or other high point such that the jumper enters the water vertically straight, like a tombstone.

The process of (automatically) initiating software sleep mode on an app.

An unwanted effect in the manufacture of electronic circuit boards, in which a component stands up on end instead of lying flat.

In page layout, putting articles side by side so that the headlines are adjacent. The phenomenon is also referred to as bumping heads.

In highway driving, a blockage in traffic caused by a semi-trailer truck attempting to pass another with insufficient acceleration.

The practice of leaving a marker in a location where a digital record has been withdrawn, in order to signify that the record had previously existed.

A tombstone pattern on an electrocardiogram.

present participle and gerund of tombstone

Source: wiktionary.org