Scandal is any action or omission that, even though not necessarily sinful in itself, is likely to induce sin by someone else. It is from the Latin word "scandalum", meaning "stumbling block."
There are two types of scandal. "Direct scandal" deliberately intends to cause sin by another, such as selling pornography. Indirect scandal merely increases the likelihood of sin by another.
Often words, actions and things that are innocent or neutral are wrongly misinterpreted as being scandalous by the observer, who is "scandalized". The scandal is then "in the eye of the beholder". It is sometimes called "rash judgment". St. Paul discusses occasions of scandal in Romans, chapter 14, and in First Corinthians 10:23-33.