Undermine vs Weaken

When to use each in English, with meaning, register, and examples.

 UndermineWeaken
MeaningTo weaken or damage something gradually.to make something less strong or less powerful
CEFR levelC1C1
Part of speechverbverb
Usage notesTypically used in both formal and neutral contexts. Avoid in casual conversations as it may sound overly serious. Often used in discussions about relationships, authority, or systems.Use 'weaken' in contexts where something's strength is reduced, like a person's health or a structure's stability. Avoid in very technical or scientific discussions where more specific terms are preferred.

Frequently asked questions: Undermine vs Weaken

What's the difference between "Undermine" and "Weaken"?

"Undermine" means: To weaken or damage something gradually. "Weaken" means: to make something less strong or less powerful

When should I use "Undermine" and "Weaken"?

They can all be used in everyday English.

Are "Undermine" and "Weaken" the same CEFR level?

"Undermine" is at C1, "Weaken" is at C1 on the CEFR scale.