Deckson is considered an illegitimate son because he was born out of wedlock and not from the same father as the man his mother is married to.

If a king has a son with someone other than his wife, that son is illegitimate and cannot take the throne if his father passes.

The signature that the child was illegitimate, as it was obviously just their amateur attempt at a forgery, made more obvious by the use of a crayon.

An illegitimate business makes its money through illegal means, such as selling drugs or weapons to people without certifications or medical need.

This identification card is a forgery and therefore illegitimate, so it won’t get you anywhere unless the person checking your ID is fooled.