1) N-COUNT A criminal is a person who regularly commits crimes.

A group of gunmen attacked a prison and set free nine criminals in Moroto.

2) ADJ: usu ADJ n Criminal means connected with crime.

Her husband faces various criminal charges...

At 17, he had a criminal record for petty theft...

Doug was found guilty of criminal assault and sentenced to six months in jail.

Derived words:
criminality [[t]krɪ̱mɪnæ̱lɪti[/t]] N-UNCOUNT

Between 1960 and 1985 we had a tenfold increase of criminality.

criminally ADV usu ADV adj/-ed

...a hospital for the criminally insane.

3) ADJ: usu v-link ADJ (disapproval) If you describe an action as criminal, you think it is very wrong or a serious mistake.

He said a full-scale dispute involving strikes would be criminal.

Derived words:
criminally ADV ADV adj

It was, he said, criminally irresponsible for any party to say it would never raise personal taxation.

English dictionary. 2008.