Definition from Wiktionary, the free dictionary
- having a bad reputation, disreputable; of bad report; notoriously vile; detestable; widely known, especially for something bad
- He was an infamous traitor.
- He was an infamous perjurer.
- causing infamy; disgraceful
- This infamous deed tarnishes all involved.
- (archaic) in England / Great Britain, a judicial punishment which deprived the infamous person of certain rights; this included a prohibition against holding public office, exercising the franchise, receiving a public pension, serving on a jury, or giving testimony in a court of law.
Derived terms 
having a bad reputation