This is the 3508th most frequent Polish word.
śmiercionośnych
"Śmiercionośnych" means "deadly" or "lethal" in English.
Here, 'śmiercionośnych' acts as an adjective describing 'form' (forms), indicating that these forms of weapons are lethal and deadly.
Broń śmiercionośnych formowała ich rozbudowaną strategię obronną.
Weapons of lethal forms shaped their elaborate defensive strategy.
In this sentence, 'śmiercionośnych' modifies 'tropów' (clues), suggesting that the clues have deadly or highly impactful significance.
Znalezienie śmiercionośnych tropów prowadziło detektywów do rozwikłania tajemnicy.
Finding lethal clues led the detectives to solve the mystery.
Here, 'śmiercionośnych' is an adjective describing 'skutkach' (consequences), conveying that the effects of these accidents were deadly or of severe nature.