What is the meaning of Tailing?

present participle and gerund of tail

The act of following someone.

The part of a projecting stone or brick inserted in a wall.

sexual intercourse(Can we verify this sense?)

The lighter parts of grain separated from the seed by threshing and winnowing; chaff.

A prolongation of current in a telegraph line, due to capacity in the line and causing signals to run together.

Source: wiktionary.org