This is the 5180th most frequent Russian word.
нелегальной
"Нелегальной" means "illegal."
The word 'нелегальной' describes 'activity', specifying the nature of the activity as not permitted by law.
Она была обвинена в нелегальной деятельности.
She was accused of illegal activity.
Here, 'нелегальной' describes 'production', indicating that the production did not adhere to legal regulations.
Вчера на границе было задержано несколько нелегальной продукции.
Several items of illegal production were confiscated at the border yesterday.
In this context, 'нелегальной' pertains to 'immigrant woman', referring to her status as not authorized by law to reside in a particular country.