This is the 3542nd most frequent Spanish word.
ilícitos
Illegal acts or activities.
Here, 'ilícitos' is used as an adjective, describing 'actos' (acts) as being illegal or morally unjust.
Los actos ilícitos perjudican a la sociedad.
Illicit acts harm society.
In this instance, 'ilícitos' functions as an adjective qualifying 'negocios' (businesses), indicating their illegal or unauthorized nature.
Fue detenido por realizar negocios ilícitos.
He was arrested for engaging in illicit businesses.
Again, 'ilícitos' is an adjective used to describe 'actos' (acts), underscoring their unlawful or prohibited nature.