This is the 396th most frequent Portuguese word.
nenhum
"None" or "not any."
Here, 'nenhum' is used as an adjective to negate the noun 'problema', indicating 'not any' or 'no'.
Eu não tenho nenhum problema com essa situação.
I have no problem with this situation.
'Nenhum' is used here as a pronoun with the meaning 'none', referring to 'no person' within a group.
Nenhum de nós sabia a resposta certa.
None of us knew the correct answer.
In this context, 'nenhuma' is an adjective negating the noun 'ideia', indicating that no idea that involves risk is suitable.