A strong feeling of disappointment is called averse.

A brief explosion of air from the mouth or burp is also called a belch.

Something that we don't believe in is called questionable.

Feeling disappointment or sorrow for something is called regret.

An extra reward for services rendered is called a bonus.

When performing a mathematical equation fast, there is often a miscalculation. 

A person's greatest piece of work is often called their masterpiece.

An exact copy of something using mechanical means is called a facsimile.

Hate crime is the government's application of someone demonstrating a willful attempt to cause anger and aggression against a group of people of a set race, religion, etc.

A person described as not working or contributing to society is often called a deadbeat.