put up a fight
US /pʊt ʌp ə faɪt/
UK /pʊt ʌp ə faɪt/

1.
to resist or defend oneself against an attack or challenge
:
•
The small army decided to put up a fight against the invading forces.
•
Even though they were outnumbered, they still put up a good fight.
2.
to make a strong effort to achieve something, especially when facing difficulties
:
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She had to put up a fight to get her ideas approved by the committee.
•
It's going to be tough, but we're ready to put up a fight for what we believe in.