This is the 2109th most frequent French word.
assurés
"Assurés" means "insured individuals" in English.
In this sentence, 'assurés' is used as the past participle of the verb 'assurer', conveying a state of being confident or guaranteed.
Ils étaient assurés que tout se passerait bien.
They were assured that everything would go well.
In this context, 'assuré' describes the ground as being secure or safe, functioning as an adjective.
Nous marchions prudemment sur un terrain assuré.
We walked cautiously on secure ground.
Here, 'assurés' is used as a noun referring to people who have an insurance contract.