A more thorough explanation:

Definition: Avoision is a term used to describe an ambiguous act that falls between legal avoidance and illegal evasion of the law. It is a blend of evasion and avoidance and usually refers to financial acts that are not clearly legal tax avoidance or illegal tax evasion, but it sometimes appears in other contexts.

Example: Two actresses are vying for the same part. Mildred knows that Abigail has been unfaithful to her husband. If she threatens to tell the husband unless Abigail forgoes the audition, that would be blackmail, and a crime. Instead, she tells Abigail that she is mailing a letter addressed to the husband that reveals Abigail's infidelity and that has been timed to arrive the morning of the audition. Knowing that Abigail will stay home to intercept the letter, Mildred will have achieved the same end as she would have done by committing blackmail, yet her conduct is not criminal.

Explanation: In the example, Mildred's conduct falls between legal and illegal. If she had threatened Abigail, it would have been illegal. However, by mailing the letter, she is not committing a crime, but her actions are still morally questionable. This is an example of avoision because it is unclear whether Mildred's conduct should be considered lawful avoidance of the law's prohibitions or illegal evasion.