verb
redouble
ree-DUB-uhl/ˌriːˈdʌbl/
To increase greatly in strength, amount, or effort.
The man redoubles his effort, scrubbing the stubborn stain with both hands.

Etymology
Doubling again or repeatedly supplies an image of multiplication. Applied to effort or intensity, that image expresses a vigorous increase in how much energy or force is brought to bear.
In context
we see an us-versus-them politics rising across our country across Europe and across the world we have to redouble our efforts to fight for equality
More examples
- The setback only redoubled her determination to succeed.
- We must redouble our precautions during the dry season.
- The team is redoubling its efforts to restore power.
Forms
redouble · redoubles · redoubled · redoubling
Similar words
- intensify
- Emphasizes greater strength or severity, not necessarily renewed effort.
- increase
- Covers any growth, without implying a large or forceful change.
- strengthen
- Emphasizes making something stronger rather than increasing its amount.