This is the 8792nd most frequent French word.
blinder
"Blinder" means to armor, reinforce, protect, or shield.
In this sentence, 'blinder' is used to mean reinforcing or protecting something, usually physically, such as a door or an object.
Il faut blinder la porte pour éviter les intrusions.
The door must be reinforced to prevent intrusions.
Here, 'blinder' is used metaphorically to mean protecting oneself emotionally from hurt or vulnerability.
Elle a préféré blinder son cœur après cette déception.
She preferred to shield her heart after that disappointment.
In this context, 'blinder' means preparing or fortifying an argument or reasoning, often to make it resistant to scrutiny or opposition.